Conservation and Substitution

Technology for Critical Materials

Volume II

Proceedings of Public Workshop sponsored by

U.S. Department of Commerce/National Bureau of Standards

and U.S. Department of the Interior/Bureau of Mines

15-17 June 1981

Vanderbilt University

Nashville, TN

April 1982

t

- QC- , 2(JQ S. DEPARTMENT OF COMMERCE

i U56 ATIONAL BUREAU OF STANDARDS

| 12-2495

V.2

1922

NBSIR 82-2495

CONSERVATION AND SUBSTITUTION

TECHNOLOGY FOR CRITICAL MATERIALS

VOLUME II

Proceedings of Public Workshop sponsored by

U.S. Department of Commerce/National Bureau of Standards

and U.S. Department of the Interior/Bureau of Mines

15-17 June 1981

Vanderbilt University

Nashville, TN

General Chairman:

Allen G. Gray

American Society for Metals

Adjunct Professor of Metallurgy

Vanderbilt University

Workshop Coordinator:

Robert T. Nash

School of Engineering

Vanderbilt University

Nashville, TN

April 1982

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

VOLUME I

TABLE OF CONTENTS

Page

I. Foreword F 1

II. Table of Contents TCI

Workshop Keynote Address

(1)

OPPORTUNITIES IN CONSERVATION AND SUBSTITUTION TECHNOLOGY FOR

CRITICAL MATERIALS, Allen G. Gray, American Society for Metals P 1

Current Activities in Substitution

(2) TECHNICAL ACTIVITIES AT THE NATIONAL BUREAU OF STANDARDS

RELATED TO SUBSTITUTION AND CONSERVATION, John B. Wachtman, Jr.,

Center for Materials Science, National Bureau of Standards. P 2

(3) CURRENT ACTIVITIES IN SUBSTITUTION, UNITED STATES DEPARTMENT

OF INTERIOR, BUREAU OF MINES, Ralph C. Kirby, Mineral Resources

Technology Division. P 3

(4) NASA'S ACTIVITIES IN CONSERVATION OF STRATEGIC AEROSPACE

MATERIALS, Joseph R. Stephens, NASA--Lewis Research Center. P 4

(5) CHARGE TO WORKSHOP IN RELATION TO MATERIALS POLICY LEGISLATION

(PL 96-479), John B. Wachtman, Jr., National Bureau of

Standards. P 5

Chromium--Substitution and Conservation

(6) CONSERVING CHROMIUM, David C. Goldberg, Westinghouse Electric

Corporation. P 6

(7) COMPUTER SYSTEMS FOR DEVELOPING CHROMIUM FREE STEELS FOR

HARDENABILITY, Dale H. Breen, International Harvester Co. P 7

(8) SUBSTITUTIONS FOR CHROMIUM IN STEELS FOR COIL SPRINGS,

S. T. Furr, Bethelehem Steel Corp. P 8

(9) AN UPDATE ON FE-MN-AL STEELS AS A REPLACEMENT FOR NI-CR

STAINLESS STEELS, Samir K. Banerji, Foote Mineral Co. P 9

(10) SUBSTITUTE STAINLESS STEELS WITH LESS CHROMIUM,

Joseph A. Douthett, Armco, Inc. P10

(11) SUBSTITUTION OF MODIFIED 9CR-1M0 STEEL FOR AUSTENITIC STAINLESS

STEELS, Vinod Sikka, Oak Ridge National Laboratory. Pll

TCI
Cobal t--Substitution and Conservation

(12) COBALT, A VITAL ELEMENT IN THE AIRCRAFT ENGINE INDUSTRY,

Joseph R. Stephens, NASA--Lewis Research Center. P12

(13) REDUCTION OF COBALT IN GAS TURBINE ENGINES, Dennis J. Evans,

Pratt & Whitney Aircraft Group. P13

(14) ROLE OF COBALT IN ASTROLOY (SUPERALLOY), John K. Tien and

Robert N. Jarrett, Columbia University. P14

(15) PROGRESS IN REDUCTION OF COBALT IN MAR-M247, Michael Nathal

Case Western Reserve University/NASA--Lewis Research Center P15

(16) SUBSTITUTION FOR COBALT IN HIGH SPEED STEELS--ROLE OF

PROCESSING INNOVATION, Walter T. Haswell, Jr., Colt

Industries, Crucible Inc. P16

(17) SUBSTITUTION FOR COBALT IN MAGNETIC ALLOYS,

Thomas D. Schlabach, Bell Telephone Laboratories P17

(18) BORONIZING AS A SUBSTITUTE FOR COBALT BEARING ALLOYS,

Stanley R. Scales, Hughes Tool Co. P18

Titanium--Substitution and Conservation

(19) TECHNOLOGICAL OPPORTUNITIES FOR A MORE STABLE SUPPLY OF

TITANIUM, Harris M. Burte, Air Force Materials Laboratory P19

(20) ISOSTATIC PRESSING OF COMPLEX SHAPES FROM TITANIUM AND

TITANIUM ALLOYS, Stanley Abkowitz, Dynamet Technology Inc. P20

(21) BENEFITS OF TITANIUM IN AIRFRAMES AND COMPROMISES IN SUBSTITUTION, Donald G. Goehler and Lew Wingert, Boeing

Commercial Airplane Co. P21

Tantal um--Substitution and Conservation

(22) TANTALUM AND OTHER CRITICAL ELECTRONIC MATERIALS,

Thomas D. Schlabach, Bell Telephone Laboratories. P22

(23) TANTALUM IN HIGH TEMPERATURE ALLOYS, James A. Ford and

Robert B. Herchenroeder , Cabot Corporation.

TC2
VOLUME II

Technological Opportunities for

Conservation of Critical Metals Utilizing

Metallurgical Coating Systems

(24) A PRESENTATION AT THE "WORKSHOP ON CONSERVATION AND SUBSTITUTION

TECHNOLOGY FOR CRITICAL MATERIAL," David S. Duvall, Pratt &

Whitney Aircraft Group.

(25) POTENTIAL FOR HARD FACING APPLICATION TECHNOLOGY TO CONSERVE

CRITICAL METALS, Steve J. Matthews, Cabot Corporation.

(26) POTENTIAL FOR CLADDINGS TO CONSERVE CRITICAL METALS,

James M. Glazebrook, Lukens Steel Co.

(27) CONSERVATION OF CRITICAL METALS UTILIZING SURFACE ALLOYING,

Ray J. Van Thyne, Dilex Systems

(28) ELECTRON BEAM IRRADIATION APPLIED TO CONSERVATION OF CRITICAL

MATERIALS, Joe E. Jenkins, Leybold-Heraeus Vacuum Systems, Inc.

(29) APPLICATION OF THERMAL SPRAYING PROCESSES TO CONSERVE CRITICAL

MATERIALS, Edward R. Novinski, METCO, Inc.

Opportunities for Conservation and Substitution of

Critical Metals Utilizing Rapid Solidification

Technology and Near Net Shape Processing

P24

P25

P26

P27

P28

P29

(30)

OPPORTUNITIES FOR CONSERVATION AND SUBSTITUTION OF CRITICAL

METALS UTILIZING RAPID SOLIDIFICATION TECHNOLOGY AND NEAR NET

SHAPE PROCESSING, Arden L. Bement, Jr., TRW, Inc. P30

(31) POTENTIAL OF RAPID SOLIDIFICATION FOR REDUCTION OF CRITICAL

ELEMENT CONTENT OF JET ENGINE COMPONENTS, Joseph Moore and

Colin Adam, Pratt & Whitney Aircraft Group. P31

(32) POTENTIAL OF RAPID SOLIDIFICATION FOR WROUGHT P/M ALUMINUM

ALLOYS, Walter S. Cebulak, Aluminum Company of America. P32

(33) POTENTIAL FOR NEAR NET SHAPES, J. Stainley Mosier and

Peter G. Bailey, General Electric Company P33

(34)

' OUTLOOK FOR AS-HIP'ED NEAR NET SHAPES, John Moll, Colt

Industries, Crucible Research Center. P34

TC3
Technological Opportunities to More Fully Utilize

Metals with Domestic Sources or Near Domestic

Sources as Substitutes for Critical Metals

(35) TECHNOLOGICAL OPPORTUNITIES TO MORE FULLY UTILIZE METALS WITH

DOMESTIC SOURCES OR NEAR DOMESTIC SOURCES AS SUBSTITUTES FOR

CRITICAL METALS, Horace N. Lander, Molybdenum Co. P35

(36) MOLYBDENUM AS A SUBSTITUTE FOR CRITICAL METALS,

Ralph M. Davison, Climax Molybdenum Co. P36

(37) NICKEL AS A SUBSTITUTE FOR METALS IN CRITICAL SUPPLY,

Robert J. Johnson, International Nickel Co. P37

(38) TUNGSTEN--A NEWLY NONCRITICAL METAL, C. C. Clark, AMAX

Tungsten. P38

(39) NEW APPLICATIONS OF VANADIUM IN STEELS TO SAVE COST, ALLOYING

AND ENERGY, P. L. Mangonon, Foote Mineral Co. P39

(40) NEW RECLAMATION PROCESS FOR CRITICAL METALS, William J. Boesch,

Special Metals, Inc. P40

Role of Composites in Substitution, Conservation

and Displacement of Critical Materials

(41) THE ROLE OF COMPOSITES IN SUBSTITUTION, CONSERVATION, AND

DISPLACEMENT OF CRITICAL MATERIALS, Alfred E. Brown,

Celanese Corp. P41

(42) ROLE OF COMPOSITES IN SUBSTITUTION, CONSERVATION, AND

DISPLACEMENT OF MATERIALS AND POTENTIAL FOR SUBSTITUTION IN MILITARY AND COMMERCIAL AEROSPACE, Richard N. Hadcock,

Grumman Aerospace Corp. P42

(43) POTENTIAL FOR SUBSTITUTION IN ALL USES OTHER THAN AIRCRAFT?

AEROSPACE, John P. Riggs, Celanese Corp. P43

Substitution Preparedness--

Information Stockpile on Substitution Technology

(44) SUBSTITUTION PREPAREDNESS-- INFORMATION STOCKPILE ON SUBSTITUTION

TECHNOLOGY, A. 0. Schaefer, Metal Properties Council. P44

(45) INFORMATION ANALYSIS CENTERS AND SUBSTITUTION TECHNOLOGY,

Harold Mindlin, Battelle Columbus Laboratories. P45

(46) INFORMATION AS AN ESSENTIAL ASPECT OF CONSERVATION,

H. David Chafe, American Society for Metals. P46

(47) FACTORS INFLUENCING A NATIONAL MATERIALS SUBSTITUTION

INFORMATION DATA BASE, Maurice A. H. Howes, ITT Research

Institute. P47

TC4
(48) INFORMATION REQUIREMENTS WHEN FACED WITH A MATERIAL SHORTAGE,

Bruce E. Boardman, Deere & Company. P48

(49) SUBSTITUTION PREPAREDNESS- -THE INFORMATION STOCKPILE ON

SUBSTITUTION TECHNOLOGY, John Rumble, National Bureau of

Standards. P49

(50) REQUIREMENTS FOR AN INFORMATION STOCKPILE ON SUBSTITUTION

TECHNOLOGY, Frank M. Richmond, Universal-Cyclops Specialty

Steel Div. P50

(51) SUBSTITUTION PREPAREDNESS— ROLE OF COLLEGES AND UNIVERSITIES,

Ellis D. Verink, Jr., University of Florida. P51

(52) SUMMARY AND OVERVIEW OF WORKSHOP, N. E. Promisel, Consultant

and Allen G. Gray, General Chairman. S 1

(53) SUMMARY OF FINDINGS SF1

(54) SUMMARY OF RECOMMENDATIONS R 1

(55) PROCESS EMPLOYED TO DEVELOP THE FINDINGS AND RECOMMENDATIONS PR1

(56) WRITTEN SUBMISSION TO WORKSHOP, James I. Mueller, President,

American Ceramic Society. W 1

TC5
A PRESENTATION AT THE "WORKSHOP ON CONSERVATION AND

SUBSTITUTION TECHNOLOGY FOR CRITICAL MATERIALS"

David S. Duvall

Pratt & Whitney Aircraft Div.

P24
KEYNOTE TALK

Opportunities for Conservation

of Critical Metals Utilizing

Metallurgical Coating Systems

A Presentation At The

"Workshop on Conservation and

Substitution Technology for

Critical Materials"

Nashville, Tennessee

June 15 - 17 , 1981

By

D.S. Duvall

Supervisor, Coating Development

Pratt and Whitney Aircraft

Chairman, High Alloys Committee

Welding Research Council

P24-1
INTRODUCTION

A NUMBER OF UNITED STATES INDUSTRIES FIND THEMSELVES DEPENDENT ON

USAGE OF MATERIALS WHICH , BECAUSE OF THEIR LIMITED OR TENUOUS

AVAI LAB I LI TY, ARE LABELED "CRITICAL" OR "STRATEGIC" ELEMENTS.

Consequently, considerable thought is presently focused on means of

REDUCING OUR DEPENDENCE ON THESE ELEMENTS. A DIFFICULT TASK — FOR

OUR ADDICTION IS CEMENTED BY THE DEMONSTRATED BENEFITS OF THESE

ELEMENTS IN ENHANCING MATERIAL PERFORMANCE IN A VARIETY OF WAYS ... STRENGTH. . . .SURFACE STABILITY. . . .EROSION RESISTANCE. . . .PROTECTION

AGAINST WEAR,

As AN EXAMPLE, A MODERN GAS TURBINE POWERPLANT FOR AIRCRAFT PROPULS I ONTHE F100 ENGINE USED TO POWER THE U.S. Al R FORCE F-15 AND F~16 FIGHTER

AIRCRAFT — IS DEPENDENT ON MANY "CRITICAL" MATERIALS. BUILDING THIS

ENGINE REQUIRES ALLOYS CONSTRUCTED OF SIGNIFICANT AMOUNTS OF ELEMENTS

DEEMED "STRATEGIC" BECAUSE OF THEIR EXTERNAL (AND POTENTIALLY VULNERABLE) SOURCES OF SUPPLY (FIGURE 1):

• Nickel

• Titanium

• Chromium

• Cobalt

• Columbium

• Tantalum

5204 LBS.

5366 lbs

1656 lbs

910 lbs.

171 LBS.

3 LBS.

Titanium's benefits are well known — an element extending lightweight

MATERIAL USAGE TO 1100°F AND ABOVE. NlCKEL, CHROMIUM, AND COBALT ARE

CORE ELEMENTS OF THE "SUPERALLOY" CLASS OF HEAT RESISTANT MATERIALS

P24-2
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WHICH PROVIDE LONG LIFE SERVICE AT TEMPERATURES UP TO 2000°F AND

ABOVE. COLUMBIUM AND TANTALUM ENHANCE SUPERALLOY BEHAVIOR, In

COOLER PORTIONS OF THE ENGINE , CHROMIUM-CONTAINING ALLOYS AND

COATINGS PROVIDE CORROSION PROTECTION WHILE COBALT, CHROMIUM,

TANTALUM AND TUNGSTEN (ANOTHER STRATEGIC ELEMENT) ARE EMPLOYED IN

HARDFACING DEPOSITS WHICH IMPART WEAR RESISTANCE.

The effect of a long term cut-off in the supply of one or more of

THESE CRITICAL ELEMENTS IS SEEN FROM THE FOLLOWING EXAMPLE. DURING

1979, APPROXIMATELY 83% OF ALL COMMERCIAL AIRLINE FLIGHTS IN THE

United States were in aircraft powered by the Pratt & Whitney JT8D

ENGINE. A CUT-OFF IN COBALT SUPPLIES WOULD EXHAUST THE PIPELINE OF

SPARE PARTS SUCH AS THE FIRST STAGE TURBINE VANE (WHICH CONTAINS

60 PERCENT COBALT) IN ABOUT 12 MONTHS, At THAT POINT, THE JT8D

POWERED FLEET WOULD START TO BE GROUNDED AT THE RATE OF 25 PERCENT

PER YEAR UNLESS SATISFACTORY ALTERNATE MATERIALS WERE FLIGHT

QUALIFIED AND "WAITING ON THE SHELF".

To REDUCE OUR VULNERABILITY, WE BELIEVE THAT A CONCERTED EFFORT WILL

BE REQUIRED BY THE GOVERNMENT, PRODUCERS, AND USERS OF STRATEGIC

MATERIALS IN THE FOLLOWING AREAS (FIGURE 2):

• Substitution

• Conservation

• Increased Domestic Production

• Improved Usage of National Stockpiles

P24- 3
-3-

In addition, information is needed on the potential utility of

METHODS LESS CONVENTIONAL THAN DIRECT ELEMENTAL OR ALLOY SUBSTITUTION, In ESSENCE, WE NEED TO ENHANCE OUR PREPAREDNESS THROUGH

"STOCKPILING" ALTERNATE TECHNICAL APPROACHES ,

EFFECT OF STRATEGIC ELEMENTS ON SURFACE PROPERTIES

One such approach involves treatments to metallurgically modify

MATERIAL SURFACES — RESTRICTING USE OF CRITICAL ELEMENTS TO SURFACE

LAYERS ONLY, FOR EXAMPLE, STRATEGIC ELEMENTS ARE WIDELY USED TODAY

TO IMPROVE ALLOY SURFACE PROPERTIES IN OXIDATION, CORROSION, EROSION,

and wear (Figure 3), Chromium, cobalt, and tantalum greatly

INCREASE THE HIGH TEMPERATURE OXIDATION AND HOT CORROSION RESISTANCE

OF SUPERALLOYS, FIGURE 4 ILLUSTRATES THE INCREASED OXIDATION AND HOT

CORROSION RESISTANCE OF PRATT & WHITNEY AIRCRAFT'S NEW TANTALUM

CONTAINING SINGLE CRYSTAL TURBINE AIRFOIL ALLOY A5A COMPARED TO

FlAR-M 200+Hf -- A CURRENT TANTALUM-FREE TURBINE AIRFOIL ALLOY. IT.IS

ALSO WELL KNOWN THAT IRON, NICKEL, AND COBALT ALLOYS NEED APPRECIABLE

AMOUNTS OF CHROMIUM TO RESIST LOWER TEMPERATURE CORROSION.

An alternate approach (Figure 5) for achieving suitable surface

STABILITY IS TO COAT, CLAD, OR OTHERWISE METALLURGICALLY MODIFY THE

EXPOSED SURFACES REQUIRING PROTECTION, In THE IDEAL CASE, COMPONENTS

EXPOSED TO HARSH ENVIRONMENTS COULD BE CONSTRUCTED OF "STRATEGI CMETAL-LEAN" STRUCTURAL ALLOYS LEAVING ONLY A SMALL QUANTITY OF

CRITICAL ELEMENT(S) TO BE CONCENTRATED AT OUTER LAYERS, THE BENEFITS

P24-4
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OF SUCH AN APPROACH WOULD BE CONSIDERABLE — ALLOWING SUBSTANTIAL

CONSERVATION OF STRATEGIC MATERIALS. HOWEVER, IT MUST ALSO BE

RECOGNIZED THAT THIS METHOD INTRODUCES RISKS OR PERCEIVED RISKS

SINCE SUBSTANTIVE FIELD EXPERIENCE DOES NOT EXIST WITH THIS APPROACH

IN MANY APPLICATIONS.

The principal concern is the consequence of defeat or premature

REMOVAL (SPALLING, ETC.) OF THE SURFACE LAYER. WOULD SUCH A LOSS

LEAD TO RAPID ATTACK OF THE UNDERLYING STRUCTURAL MATERIAL AND

RESULT IN A CATASTROPHIC FAILURE OF THE COMPONENT? To BE ACCEPTABLE,

THE SURFACE TREATMENT APPROACH REQUIRES CONSIDERABLE FORETHOUGHT.

Also, a base of experience is needed from which to draw confidence

IN SURFACE LAYER PERFORMANCE DURING SERVICE.

MATERIAL SURFACE MODIFICATIONS - CURRENT STATUS

Fortunately, considerable experience already exists through the longtime, WIDESPREAD, AND GROWING USE OF SURFACE TREATMENTS IN MANY

INDUSTRIES AND A VARIETY OF PROCESSES FOR CREATING THEM. SURFACE

TREATMENTS RANGING IN THICKNESS FROM ANGSTROMS TO INCHES ARE

PRESENTLY UTILIZED TO EITHER REDUCE COST (ALLOWING USE OF LESS

EXPENSIVE STRUCTURAL ALLOYS) OR TO ENHANCE RESISTANCE AGAINST

OXIDATION, CORROSION, EROSION, OR WEAR. FOR INSTANCE, THIN (ANGSTROMS

OR MICRONS) DEPOSITS OF CHROMIUM PROVIDE PROTECTION FOR AUTOMOTIVE

COMPONENTS AND ALLEVIATE THE NEED FOR MORE EXPENSIVE STAINLESS STEELS.

At the other extreme, large components such as flue gas scrubbers for

ELECTRIC POWERPLANTS ARE NOW BEING FABRICATED BY EXPLOSIVELY CLADDING

1/ 8

- 1/2 INCH LAYERS OF STAINLESS STEELS OR NICKEL-CHROMIUM ALLOYS TO

P24-5
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THE SURFACES OF CARBON STEEL STRUCTURES TO PROVIDE CORROSION

RESISTANCE AT REDUCED COST,

IN TODAY'S AIRCRAFT GAS TURBINE POWERPLANT, METALLURGICAL COATINGS

AND SURFACE TREATMENTS ARE EXTENSIVELY EMPLOYED NOT SO MUCH TO REDUCE

COST BUT TO MAXIMIZE THE SURFACE STABILITY OF THE BEST STRUCTURAL

ALLOYS AVAILABLE (FIGURE 6), TAILORED SURFACE COMPOSITIONS ARE USED

ON AIRFOILS IN THE HIGH PRESS URE TURB I NE SECTION TO INCREASE OXIDATION

AND HOT CORROSION RESISTANCE, CERAMIC COATINGS PROVIDE THERMAL

INSULATION FOR COMBUSTOR AND AFTERBURNER COMPONENTS. HARDFACE

DEPOSITS ARE USED THROUGHOUT THE ENGINE TO RESIST A VARIETY OF FORMS

OF WEAR, Also , ELECTROPLATED layers (e,g., nickel-cadmium) are used

TO RESIST CORROSIVE ATTACK IN LOWER TEMPERATURE ENGINE REGIMES,

It is worthwhile to examine current gas turbine engine surface treatments IN MORE DETAIL TO APPRECIATE TODAY'S STATE-OF-THE-ART IN THIS

TECHNOLOGY, FOR EXAMPLE, METALLURGICAL COATINGS HAVE BEEN EMPLOYED

SINCE THE EARLY 1960 ' S TO RETARD OXIDATION AND HOT CORROSION OF

TURBINE AIRFOILS, IMPROVEMENTS IN COMPONENT LIVES UP TO A FACTOR OF

TEN OR MORE HAVE BEEN REALIZED BY THESE TREATMENTS. INITIALLY, THEY

CONSISTED OF SURFACE ENRICHMENT IN ALUMINUM AND/OR CHROMIUM BY

DIFFUSION PROCESSES (FIGURE 7), SUBSEQUENT ADVANCES IN ALLOY DEVELOPMENT ( I , E .

DIRECTIONAL SOLIDIFICATION, SINGLE CRYSTALS) HAS LED TO

A GENERATION OF TURBINE AIRFOIL MATERIALS WHOSE MECHANICAL PROPERTIES

FAR OUTSTRIP THEIR CAPABILITY TO RESIST HIGH TEMPERATURE SURFACE

DEGRADATION

Improved coatings were needed in order to fully utilize the high

TEMPERATURE CAPABILITY OF THOSE NEW MATERIALS; THIS LED TO THE

DEVELOPMENT OF A FAMILY OF 3-10 MILS THICK VAPOR DEPOSITED OVERLAY

P24-6
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COATINGS WITH COMPOSITIONS TAILORED TO ACHIEVE THE MAXIMUM

ATTAINABLE ENVIRONMENTAL RESISTANCE. THESE COATINGS, KNOWN AS

MCrAlY's (where M=nickel, cobalt and/or iron, Cr=chromium,

Al=ALUMINUM, AND Y=YTTRIUM) PROVIDE UP TO 10 TIMES THE PROTECTION

AVAILABLE WITH PREVIOUS S URFACE-DI FFUS I ON-ENRI CHED TREATMENTS.

Today, most high-pressure turbine blades and vanes in military and

COMMERCIAL GAS TURBINE ENGINES ARE PROTECTED BY SURFACE DIFFUSION

OR OVERLAY COATINGS; YET IMPROVEMENTS IN THE DURABILITY OF THESE

SURFACE TREATMENTS COULD BE IMMEDIATELY TRANSLATED INTO BETTER

ENGINE PERFORMANCE AND COMPONENT LIFE.

We have also employed plasma sprayed ceramic coatings for many years

TO THERMALLY INSULATE SHEET METAL COMPONENTS IN COMBUSTOR AND AFTERBURNER COMPONENTS (FIGURE 8). THESE "THERMAL BARRIERS" TYPICALLY

CONSIST OF APPROXIMATELY 5 MILS OF AN OXIDATION-RESISTANT METALLIC

UNDERLAYER COVERED BY 10-20 MILS OF A ZIRCONIA COMPOSITION OR A

MIXTURE OF THE METALLIC AND CERAMIC CONSTITUENTS. THESE COATINGS

HAVE GREATLY EXTENDED THE LIFE OF THE CHROMIUM AND COBALT-RICH

MATERIALS USED IN THESE APPLICATIONS. EVEN MORE SIGNIFICANT BENEFITS

COULD BE ACHIEVED BY EXTENSION OF THIS TECHNOLOGY TO TURBINE SECTION

AIRFOILS

Today's gas turbine engine also provides many opportunities for

METAL-TO-METAL WEAR, WHICH, IF UNCHECKED, CAN LEAD TO LOSS OF

PERFORMANCE, PREMATURE COMPONENT LIFE, OR PART FAILURE. WEARRESISTANT SURFACE TREATMENTS HAVE BEEN SUCCESSFULLY UTILIZED SINCE

P24-7
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THE INTRODUCTION OF JET ENGINES TO COMBAT THIS PROBLEM (FIGURE 9),

Many of these treatments involve surface deposits of cermets

CONSISTING OF CHROMIUM, TUNGSTEN, OR TANTALUM CARBIDES IN A COBALT

MATRIX, They are typically fabricated by welding or thermal

spraying, These are long-practiced examples of strategic-metalrich SURFACE TREATMENTS GUARDING STRUCTURAL ALLOY LIFE; YET THE

BIGGEST CHALLENGE TODAY IN THIS TECHNOLOGY IS TO REDUCE THE CRITICALMETAL CONTENT (AND COST) OF THESE WEAR RESISTANT MATERIALS,

In the cooler portions of today's aircraft gas turbine, several

COMPONENTS ARE DEPENDENT ON THIN SURFACE COATINGS TO PROVIDE

PROTECTION AGAINST AQUEOUS CORROSION. ELECTROPLATED OR SLURRY

SPRAYED LAYERS OF NICKEL-CADMIUM, CHROMIUM, OR ALUMINUM PREVENT

SURFACE ATTACK OF CRITICAL STRUCTURES SUCH AS SHAFTS AND COMPRESSOR

BLADES AND VANES, In MANY CASES, HOWEVER, THE COMPONENT BEING

PROTECTED IS AN IRON OR NICKEL ALLOY ALREADY CONTAINING A SUBSTANTIAL

AMOUNT OF CHROMIUM TO PROVIDE INHERENT ENVIRONMENTAL RESISTANCE

INDEPENDENT OF SURFACE ALLOYING. THIS IS ANOTHER EXAMPLE OF THE

CURRENT DESIGN APPROACH WHICH AIMS TO ACHIEVE THE MAXIMUM DURABILITY

PLUS SAFETY MARGINS POSSIBLE BY USE OF ALL THE BEST AVAILABLE

MATERIALS

SURFACE TREATMENTS TO REDUCE STRATEGIC MATERIAL CONSUMPTION

The widespread, successful use of surface treatments provides a

CONFIDENCE BASE FOR EXTENSION OF THIS APPROACH TO FUTURE CONSERVATION OF STRATEGIC MATERIALS IN MANY INDUSTRIES. In JET ENGINES,

P24-8
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SEVERAL OPPORTUNITIES EXIST TO REDUCE CRITICAL MATERIALS IN

TURBINE STRUCTURES THROUGH RELIANCE ON SURFACE COATINGS. THIS

WILL REQUIRE, HOWEVER, A PHILOSOPHICAL CHANGE TO A CONCEPT WHICH

ACCEPTS ONLY ONE BARRIER AGAINST ENVIRONMENTAL OR SURFACE ATTACK.

Obviously, the benefits of such an approach must be extremely

PERSUASIVE TO OVERRULE PRESENT DESIGN PRACTICE.

The recent cobalt and tantalum shortages have already affected

SURFACE TREATMENT TECHNOLOGY. A CONSIDERABLE EFFORT IS UNDERWAY,

FOR INSTANCE, TO REDUCE THE COBALT CONTENT OF PRESENT WEAR-RESISTANT

SURFACE ALLOYS. NEW HARDFACING COMPOSITIONS HAVE BEEN FORMULATED

WITH NICKEL RATHER THAN COBALT MATRICES. THE TANTALUM CARBIDES IN

THESE WEAR-RESISTANT ALLOYS AND IN CUTTING MATERIALS HAVE ALREADY

BEEN REPLACED IN SOME INSTANCES BY TITANIUM CARBIDES AND/OR NITRIDES,

AND THROUGH USE OF MOLYBDENUM AS AN ALTERNATE REFRACTORY METAL

ADDITION

In the area of oxidation and hot corrosion resistance, Pratt &

Whitney Aircraft is evaluating the substitution of a NiCoCrAlY

TURBINE AIRFOIL COATING (23% COBALT) TO REPLACE A CURRENTLY USED

CoCrAlY (67% cobalt) composition (Figure 10). Laboratory and experimental GROUND-BASED ENGINE TESTS TO DATE HAVE BEEN SUCCESSFUL,

AND TURBINE AIRFOILS COATED WITH THE LOWER COBALT ALLOY ARE

PRESENTLY UNDERGOING FIELD SERVICE EVALUATION WITH COMMERCIAL AIRLINES.

If the substitute coatings' durability is verified, a yearly savings

OF 10,000-20,000 LBS. OF COBALT COULD BE REALIZED -- A MODEST BUT

P24-9
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INTERESTING CONSERVATION IN A MATERIAL EMPLOYED AS A 5 MI L THICK

LAYER,

The greatest potential exists, of course, in using surface treatments IN CONJUNCTION WITH STRATEGIC-METAL-LEAN STRUCTURAL ALLOYS,

We are presently examining concepts to impart oxidation and hot

CORROSION RESISTANCE TO POTENTIAL TURBINE AIRFOIL MATERIALS WHICH

HAVE LOW CRITICAL MATERIAL CONTENT. PRELIMINARY EXPERI MENTS, US I NG

TAILORED METALLIC COATINGS, HAVE BEEN PROMISING, BUT CONSIDERABLE

DEVELOPMENT IS REQUIRED BEFORE SUCH A SYSTEM CAN BE UTILIZED,

Ceramic thermal barrier coatings also offer a means to maintain

HEAT RESISTANCE WHILE REDUCING CRITICAL METAL CONTENT IN TURBINE

COMPONENTS, THIN (E.G. 5-20 MILS) LAYERS OF CERAMICS SUCH AS

ZIRCONIA CAN REDUCE THE TEMPERATURE OF AIR-COOLED TURBINE AIRFOILS

BY AS MUCH AS 300°F (FIGURE 11), In THEORY, THIS AMOUNT OF INSULATION CAN BE TRANSLATED INTO A REQUIREMENT FOR UP TO 300°F LESS

HEAT RESISTANCE (STRENGTH, ENVIRONMENTAL RESISTANCE) IN THE UNDERLYING STRUCTURAL ALLOY. POTENTIALLY, CRITICAL-ELEMENT ALLOYING

ADDITIONS COULD BE CORRESPONDINGLY REDUCED,

The risks of such AN APPROACH ARE OBVIOUS; however, failure of

THE CERAMIC COATING COULD LEAD TO RAPID OVERHEATING. SEVERAL

PROGRAMS ARE CURRENTLY BEING CONDUCTED UNDER INDUSTRY AND GOVERNMENT

SPONSORSHIP TO INCREASE THE RELIABILITY OF CERAMIC GAS TURBINE

coatings. At Pratt & Whitney Aircraft, we have been able to increase

P24-10
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THE RESISTANCE TO CERAMIC SPALLING UNDER HARSH TURBINE AIRFOIL

CONDITIONS FROM A FEW HUNDRED THERMAL CYCLES TO UPWARDS OF 20,000

cycles, Nevertheless, considerably more experience and confidence

ARE REQUIRED BEFORE THERMAL BARRIER COATINGS CAN BE USED AS A SUBSTITUTE FOR today's STRATEGIC-ELEMENT RICH SUPERALLOYS,

As PREVIOUSLY DISCUSSED, PROTECTION FROM AQUEOUS CORROSION CAN BE

ACHIEVED THROUGH CHROMIUM-RICH SURFACE TREATMENTS, A REVISITATION

OF THIS APPROACH IS ILLUSTRATED IN FIGURE 12, Up TILL NOW, HOWEVER,

THIS TECHNIQUE HAS BEEN VIEWED AS A "CHEAP" SUBSTITUTE — BE IT IN

A WIDESPREAD CONSUMER PRODUCT OR A HIGH TECHNOLOGY DEVICE. In GAS

TURBINE CONSTRUCTION, CHROMIUM SURFACE ENRICHMENT HAS GENERALLY

BEEN UTILIZED TO ENHANCE THE DURABILITY OF ALREADY RESISTANT

MATERIALS, A CHANGE TO COMPLETE DEPENDENCE ON CHROMIUM-RICH SURFACES

WOULD PROVIDE SUBSTANTIAL SAVINGS OF A CRITICAL ELEMENT BUT, LIKE

CERAMIC THERMAL BARRIER COATINGS, NEEDS CONSIDERABLY GREATER

CONFIDENCE IN RELIABILITY THAN EXISTS TODAY.

The potential for wear-resistant surface treatments to reduce

STRATEGIC-METAL USAGE IN GAS TURBINES APPEARS RATHER LIMITED SINCE

SURFACE DEPOSITS ARE ALREADY THE PRINCIPAL MEANS OF COMBATING SUCH

problems. There are a few applications, however, where new metallurgical OR CERAMIC COATINGS MAY BE BENEFICIAL. As AN EXAMPLE,

Pratt & Whitney Aircraft currently utilizes a cobalt-base alloy as

A SEAL MATERIAL BETWEEN ROTATING HIGH-PRESSURE TURBINE BLADES AND THE

P24-11
- 11-

EXTERNAL ENGINE CASE (FIGURE 13), A RECOGNIZED ADVANTAGE OF THIS

SEAL MATERIAL IS THE "LUBRICITY" OF THE COBALT OXIDE IT FORMS AS

OPPOSED TO THE OXIDES WHICH WOULD BE CREATED ON ALTERNATE HEATRESISTANT MATERIALS BASED ON NICKEL, If A COBALT-RICH SURFACE

TREATMENT WAS SUBSTITUTED TO PROVIDE THE DESIRED "LUBRICITY", WE

ESTIMATE THAT A YEARLY SAVINGS OF APPROXIMATELY 20,000 LBS. OF

COBALT WOULD BE ACHIEVED IN PRATT & WHITNEY AIRCRAFT ENGINES ALONE.

Surface treatments may also be able to conserve critical elements

BY PROVIDING RESISTANCE TO PARTICULATE EROSION. A PROGRAM IS

PRESENTLY BEING CONDUCTED UNDER NASA SPONSORSHIP TO DEVELOP COATINGS

TO RETARD JET ENGINE COMPRESSOR AIRFOIL EROSION — LOSS OF MATERIAL

WHICH DEGRADES ENGINE EFFICIENCY AND REQUIRES REPLACEMENT OF THESE

TITANIUM, IRON-CHROMIUM, AND NICKEL-CHROMI UM COMPONENTS , THIS

EROSION PROBLEM MAY BECOME MORE SERIOUS IN THE FUTURE IF ELECTRICAL

GENERATING TURBOMACHINERY USE COAL-DERIVED FUEL CONTAINING SIGNIFICANT

PARTICULATE MATTER. FIGURE 1A SHOWS THE DIFFERENCE IN THE AMOUNT OF

METAL LOSS BETWEEN COBALT-TUNGSTEN CARBIDE COATED AND UNCOATED

TITANIUM COMPRESSOR BLADES AFTER EXPOSURE IN A LABORATORY EROSION

TEST. It is projected that such coatings could double compressor

AIRFOIL LIFE. ESTIMATES SUGGEST THAT THIS IMPROVEMENT WOULD DECREASE

THE YEARLY AMOUNTS OF TITANIUM AND CHROMIUM NEEDED TO MAKE REPLACEMENT

HIGH COMPRESSOR BLADES FOR THE JT8D AND JT9D AIRCRAFT ENGINES BY

ROUGHLY 90,000 LBS, AND 10,000 LBS., RESPECTIVELY, In OTHER ENGINES,

THE RELATIVE SAVINGS OF TITANIUM AND CHROMIUM WOULD VARY DEPENDING

ON THE RATIO OF TITANIUM TO STEEL OR NICKEL COMPRESSOR BLADES.

P24-12
- 12 -

However, before such coatings can be employed, it must be demonstrated THAT THEY WILL NOT COMPROMISE COMPONENT MECHANICAL PROPERTIES

SUCH AS FATIGUE STRENGTH. As WITH THE OTHER EXAMPLES DISCUSSED,

USE OF EROSION-RESISTANT SURFACE TREATMENTS TO CONSERVE STRATEGIC

MATERIAL USAGE WILL BE DEPENDENT ON CONFIDENCE THAT THE INTEGRITY

OF THE BASIC STRUCTURE WILL NOT BE IMPAIRED.

RECOMMENDATIONS

Several materials substitutions have occurred throughout industry

SINCE THE RECENT COBALT AND TANTALUM SHORTAGES. FORTUNATELY, THE

RECENT CRISIS HAS PERMITTED TIME FOR INCORPORATION OF SUBSTITUTIONS.

This luxury would not exist, obviously, in the event of a complete

CUT-OFF OF A STRATEGIC ELEMENT SUPPLY.

The recent disruptions of imported fuel and mineral supplies forewarn

OF THE NEED TO PREPARE AGAINST POSSIBLE COMPLETE CUTOFFS — SUDDEN

SHOCKS WHICH COULD NOT BE DAMPENED BY SUPPLY/DEMAND ADJUSTMENTS.

For many products, the long lead times needed to validate substitute

MATERIALS WOULD RESULT IN PRODUCTION STOPPAGE, NOT SHORTAGES.

"Stockpiling" of demonstrated alternatives would provide one

CUSHION AGAINST SUCH AN ECONOMIC OR STRATEGIC CRISIS. METALLURGICAL

SURFACE TREATMENTS CAN BE AN IMPORTANT PART OF SUCH A STOCKPILE

(Figure 15)

As PREVIOUSLY POINTED OUT, RELIABILITY WILL BE THE KEY QUESTION

GOVERNING USE OF A PARTICULAR SURFACE TREATMENT TO REPLACE OR

P24-13
- 13-

conserve STRATEGIC ELEMENTS IN UNDERLYING STRUCTURAL ALLOYS.

Demonstrated confidence would be needed at the onset of any

FUTURE STRATEGIC METAL CRISIS; UNACCEPTABLY LONG TIMES WOULD BE

REQUIRED TO ACHIEVE THIS AFTER A SUPPLY SHOCK OCCURRED. ECONOMIC

CONSIDERATIONS UNFORTUNATELY WILL NOT PERMIT EACH POTENTIALLY

BENEFICIAL SURFACE TREATMENT TO BE EXPERIMENTALLY CONFIRMED AHEAD

OF TIME, AS AN EXAMPLE, QUALIFICATION OF A NEW AIRFOIL COATING

FOR AN AIRCRAFT GAS TURBINE CAN REQUIRE OVER A MILLION DOLLARS OF

ENGINE TESTING AT TODAY'S FUEL PRICES.

Any ahead-of-crisis investment in surface treatment technology

SHOULD PRUDENTLY BE MADE BASED ON HIGH PROMISED PAYOFF. At FIRST

GLANCE, MANY SURFACE TREATMENTS ARE ALLURING CONSERVERS OF CRITICAL

ELEMENTS; EFFORTS TO REALIZE THE PROMISED BENEFITS COULD BE

EXPENSIVE DISAPPOINTMENTS. THE LOGICAL FIRST STEP IS TO REALISTICALLY EVALUATE THE BENEFITS AND RISKS OF SPECIFIC SURFACE TREATMENT

TECHNOLOGIES REGARDING CRITICAL MATERIALS SUBSTITUTION. SUCH

STUDIES TO DATE ARE RARE OR NON-EXISTENT. THIS IS THE PLACE TO

BEGIN

P24-14
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FIGURE

15
POTENTIAL FOR HARD FACING APPLICATION TECHNOLOGY

TO CONSERVE CRITICAL METALS

Steve J. Matthews

Cabot Corooration

P 25
POTENTIAL FOR HARD-FACING APPLICATION TECHNOLOGY

TO CONSERVE CRITICAL METALS

S. J. Matthews

CABOT CORPORATION

Chairman, Subcommittee on Hard facing and Wear

WELDING RESEARCH COUNCIL

Presented June 16, 1981 at the Workshop on Conservation and Substitution Technology for

Critical Materials, Vanderbilt University

Session IIIB - "Technological Opportunities for Conservation

of Critical Metals Utilizing Metallurgical Coating Systems

P25-1
INTRODUCTION

The purpose of this presentation is to describe the overall concept of hard

facing as an effective method of wear control, and to discuss the application

of this technology to conserve critical materials. The basic theme of this

presentation is that cheaper, less strategic base materials can be made

serviceable in harsh wear environments, provided the surfaces are protected by

application of a wear resistant weld overlay material.

DEFINITION OF HARD FACING

Hard facing is a term describing the application of a hard material to the

surface of a component by welding (or by an allied welding process) for the

main purpose of reducing wear. Wear can be defined as the loss of material by

abrasion, impact, erosion, cavitation, galling, or metal-to-metal adhesion.

It should be recognized that wear is a surface phenomenon. As the surface of

a component wears away, it usually becomes less efficient or even disabled,

usually because of loss of dimensional clearance or configuration. The annual

cost of "wear" to the United States economy is estimated to be about $60

billion dollars, rivaling another well known destructive nemesis: corrosion.

There is a wide variety of tribologically different types of wear, each with

their own mechanisms. "Tribology" is a term coined to describe the science of

friction, wear and lubrication. The mechanical engineering community has

addressed the subject of wear for several years in this country, attacking the

problem with lubrication technology and improved mechanical designs. However,

it should be recognized that wear is dramatically compounded in harsh

environments characterized by corrosion, high temperature, high loads, and severe abrasion where lubrication technology simply won't work. It would be

meaningless for instance to "oil" the edge of a plow share for agricultural

tillage. Protection of a surface with a hard, wear resistant material is

therefore the only meaningful alternative, if wear prevention is to be pursued

in unlubricated applications.

HARD FACING PROCESSES AND DEPOSITION TECHNIQUES

Hard facing is a particular form of weld overlay surfacing. A great deal of

the welding and joining technology developed in the United States over the

last 30 years is applicable to hard facing, especially in terms of the

processes and equipment used to deposit hard-facing alloys onto a surface.

Table 1 lists the various welding processes commonly used for hard facing,

along with characteristic percent dilution and deposition rate associated with

each process. The extent of base material dilution into the hard-facing

overlay is an important feature to minimize since excessive dilution will

compromise the metallurgical effectiveness of the hard-facing material. This

invariably results in lower hardness and generally less effective wear resistance. It would be advantageous on the other hand for deposition rate to

P25-2
be high for economic reasons (i.e., less time to complete the job). There has

been a distinct trend in this country over the past 5 years towards increased

automation and mechanization, especially using the gas tungsten arc and plasma

transferred arc hardfacing processes. Mechanization serves not only to

increase productivity, but also eliminates the variable of manual fatigue,

thereby immproving product quality, consistency and reliability..

Hard-facing consumables to "feed" the various hard-facing processes have

historically been manufactured in the form of bare cast rod. The increased

trend towards automation, however, has prompted increased production of other

consumable forms, namely, continuous cast rod, continuous wires, and also

powders in the case of the plasma transferred arc process. Hard-facing alloys

are intrinsically hard and therefore make manufacturing by traditional casting

and wroughting techniques relatively difficult. The atomization of molten

metal to produce powders overcomes these difficulties, thereby suggesting even greater advantages of the plasma transferred arc process as a highly efficient

hard facing system.

HARD FACING ALLOYS

Because wear is a complex phenomenom compounded by a wide variety of different

service environments, there is no single hard facing alloy that will

universally resist all types of wear. Hence, the existence of literally

hundreds of different hard-facing alloys on the market today. Most

hard-facing alloys can be classified into one of the following general

classifications

Cobalt-base alloys

Nickel-base alloys

Iron-base alloys

Tungsten carbide composite alloys

Table 2 identifies the nominal composition of representative alloys for each

classification. It is also ironic to note that almost all hard-facing alloys,

especially the cobalt family, rely heavily on strategic materials for their

chemical make-up. A discussion of each family of materials can be given as follows

Cobalt-base Alloys

Cobalt base alloys come the closest to being "universal" hard-facing materials

since they have been industrially proven to resist not only abrasion and

me tal- to-metal wear, but are also resistant to high temperature and/or

corrosion environments. A good example is in the valve industry where both

fluid flow and automotive diesel valve seats are commonly hard faced with

cobalt alloys.

Metallurgically , these alloys contain three very strategic elements: cobalt,

chromium and tungsten. Liberal amounts of carbon are added to form a chromium

carbide network to resist abrasive wear. The cobalt matrix tends to resist

the metal-to-metal wear. The chromium in solid solution with the matrix

resists corrosion. The tungsten also in solid solution serves to increase

resistance to deformation at elevated temperatures (i.e., hot hardness).

P25-3
As a result of the 1978 "cobalt crisis, considerable efforts have been

expended on the part of hard-facing producers and users alike to find a cobalt

base alloy substitute. Using principles of physical metallurgy proven

effective in the design of high temperature and corrosion resistant alloys',

hard-facing alloy development programs have also been conducted. A number of

alloys based upon an iron-plus-nickel substitution for cobalt have been

identified, and some of these alloys have been accepted in industry for

certain applications. Based on laboratory data, these "cobalt-substitute

alloys" have been found to exhibit equivalent wear resistance (with the

exception of galling) compared with cobalt base alloys. The only practical

disadvantage has been reduced weldability characteristics (i.e., more prone to

porosity and/or cracking).

Nickel-base Alloys

Most of the traditional nickel base alloys are based upon the

nickel-chromium-silicon-boron system, and, microstructurally , are characterized by large volume fractions of hard boride phases. These alloys offer

excellent abrasion resistance, coupled with relatively good corrosion

resistance. However, they generally suffer greater loss of hot hardness and

rarely compete with cobalt base alloys at service temperatures greater than

1000°F. Galling resistance, as a rule, is also inferior. As a family of

alloys they also are more prone to cracking during hard facing deposition in

comparison to cobalt base alloys.

Iron-base Alloys

This family of alloys is often used in metal-to-metal wear environments not

compounded by corrosion or high temperature. Compositionally , they contain

relatively small amounts of chromium and tungsten to produce low or medium

alloy steel type of alloys. However, there is another family of higher

alloyed iron-based hard facing materials containing up to 30% chromium and 4%

carbon. These alloys are designed to resist earth and rock abrasion by

virture of large volume fraction of chromium carbides present in the

microstructure. Typical applications include coal and rock crushing equipment

and farm implement tools.

Tungsten Carbide Composite Alloys

These are referred to as composite alloys because the deposition method

usually involves introducing crushed tungsten carbide particles into a molten

deposit, and allowing the composite overlay to solidify. This results in a tough matrix (usually steel) plus a coarse dispersion of hard tungsten carbide

particles. Since tungsten carbide is one of the hardest materials known to

man, the alloys are used in severe abrasion conditions, such as rock drilling

bits and other cutting or chipping type applications. Tungsten carbide

readily oxidizes and, therefore, cannot be used at elevated temperatures.

P25-4
HARD FACING PHILOSOPHY

The use of hard facing today can presently be found in a wide variety of

industries, some of which are listed in Table 3. Hard facing can be applied

either at the time of original equipment manufacture (OEM) (for example , valve seats, screw flights, turbine hardware) or as a maintenance technique to

extend the life of existing equipment and components (i.e., tractor

undercarriage parts, bucket teeth, mine car wheels, etc.).

Often, it is in the OEM applications that one finds the deposition of a cobalt

base alloy, for instance, onto a highly alloyed material such as stainless

steel. From a strategic metal viewpoint, one might argue the virtue of using

even more strategic metals (i.e., cobalt) on top of something that is already

strategic (i.e., chromium in the stainless steel base material). The counter

argument is obvious. The wear resistance of the hard-facing alloy is superior

to the base material, hence one is attempting to preserve the valuable metals

within the original component by extending the service life of the equipment

indefinitely. The same philosophy is present when one buys home or auto

insurance (you pay a little more to protect your original investment).

In contrast to OEM, the "maintenance" type of hard facing is often

characterized by the application of a high chromium iron base hard facing

alloy to a mild steel base material. Proponents of conserving strategic

metals might argue against hard facing, saying it would be advantageous to

simply replace the "cheap and dirty" worn out steel with new (non-s trategic

)

steel. The fact of the matter is that Americans can no longer afford to live

in a "throw away" society. Conservation of all materials via wear protection

means not only conservation of raw materials, but also conservation of

energy. By extending the life of even a common mild steel part, via hard

facing, we have "saved" the energy that would have to be expended to replace

that part in total (i.e., energy expended to mine iron ore, transport, reduce

to metal, melt, cast, hot roll, cut, shape, etc.)

Perhaps the greatest opportunity for the application of hard-facing technology

to conserve critical materials is a "design-for-maintenance" philosophy.

Rather than attempting to design the entire body of a component out of a material highly alloyed in strategic materials, it would be wiser to construct

the part using less critical materials and then hard face the surface with

suitable alloy to resist wear. This approach even offers a little known

fringe benefit for the welding engineer. For metallurgical reasons, it is

easier to hard face mild steel than it is to hard face alloy steels and

especially martensitic stainless or precipitation hardened steels. As a rule,

mild steels can be hard faced with less preheat and no post weld heat

treatment, thereby offering an even further advantage of reduced energy

consumption.

P25-5
HARD-FACING R&D TRENDS

Considerable research and development is still needed if hard facing is to be

fully exploited as a method of conserving strategic materials. A review of

hard-facing R&D activity over the decade 1960 to 1970 reveals little or no interest expressed by the engineering community on the subject of hard

facing. However, during the following decade, 1970 to 1980, the engineering

community, especially metallurgical and welding orientated technologies, began

to take a keen look at hard facing as an effective method of wear control.

This interest, of course, was brought about by spiraling material costs,

material shortages, and long delivery times, characteristic of American

industry during the 70' s. Prior to this era, the "black art" of hard facing

had been treated rather unscientifically. Hard-facing materials and processes

had been used on a trial and error basis with little attempt to understand

basic engineering principles.

In 1975, the Welding Research Council established a new high alloy

subcommittee devoted specifically to the subject of hard facing and wear. Interest and activity in this subcommittee has grown steadily over the past

six years. Subcommittee membership enrollment alone has increased at a rate

of 20% per annum.

In 1979, the first Engineering Foundation Conference ever held in this country

devoted to the subject of "hard facing" was held at Asilomar, California. The

conference involved five days of meetings and discussions centered on hard-facing metallurgy, wear test methods, processes and applications.

Presentations highlighted a number of well executed studies already initiated

by private enterprise to explore the technology of hard facing, while many

other presentations cited the need for further work.

In 1982, a follow-up Engineering Foundation Conference will be held in

Henniker, New Hampshire. This conference will be aimed at "advances" in hard

facing technology, namely: development, process mechanization, property and wear characterizations, and hard facing applications and economics.

A further prediction for R&D activity in this country over the next decade,

1980 to 1990, should be characterized by continued interest in hard facing,

not only by the "engineering community", but also by private industry and

university researchers, hopefully in conjunction with government support.

Currently, the University of Notre Dame and the Colorado School of Mines are

the only two institutions of higher learning in this country actively involved

in some form of hard-facing research.

The continued high level of interest in hard facing during the 80 '

should

logically be prompted by the national goals of increased productivity and less

dependence on foreign resources, both energy and minerals. There is a great

potential for hard-facing technology to meet all of these goals.

P25-6
TABLE 1

WELDING PROCESSES USED FOR HARD-FACING OVERLAY

Process

Typical Base

Metal Dilution

Typical Deposition

Rates (lbs/hr)

Oxyacetylene 1 - 5% 2-3

Manual Gas Tungsten Arc 15 - 25% 2-3

Shielded Metal Arc 20 - 30% 3-5

Flux Cored Arc (open arc) 15 - 25% 8-15

Submerged Arc 30 - 50% 10 - 20

Plasma Transferred Arc 5 - 15% 5-12

P25-7
TABLE 2

NOMINAL CHEMICAL COMPOSITIONS OF REPRESENTATIVE HARD-FACING ALLOYS

General Classification Typical Composition of Representative Alloy

Co Ni Fe Cr W C Other

Cobalt-base 65 1 1 28 4 1.0 -

"Cobalt Substitute" Alloy 12 23 29 26 4 1.1 3 Mo

Traditional nickel-base 0 72 4 15 0 0.8 4.0 Si

3.5 B

Iron-base (low carbon) 0 0 92 5.5 0 0.7 -

Iron-base (high carbon) 0 0 64 30 0 3.5 1 Mo

Tungsten carbide composites 0 0 40 0 54 6.0 -

P25-8
TABLE 3

SOME INDUSTRIES WHICH USE HARD FACING AS

A METHOD OF WEAR CONTROL

Industry Typical Application

Agriculture Plow shares

Brick/ cement Chutes and conveyors

Chemical Plastic extrusion screws

Construction Bulldozer parts

Food Product Mixer Paddles

Foundry Sand mixers/slingers

Glass Bottle Mold edges and faces

Metal Forming Forging hammers

Mining/ quarrying Rock crushers

Petroleum Tool joints

Power Utility Hammer mill (coal) hammers

Steel Blast Furnace bells

Pulp and Paper Chipper knives

Valve Valve seat and trim

P25-9
POTENTIAL FOR CLADDINGS TO CONSERVE CRITICAL METALS

James M, Glazebrook

Lukens Steel Co.

P26
POTENTIAL FOR CLADDINGS TO CONSERVE CRITICAL METALS

James M. Glazebrook

Manager, Head and Clad Sales

Lukens Steel Company

P26-1
FOR PRESENTATION AT WORKSHOP ON

CONSERVATION AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS

VANDERBILT UNIVERSITY

NASHVILLE, TENNESSEE

JUNE 16, 1981

POTENTIAL FOR CLADDINGS TO CONSERVE CRITICAL METALS

COMBINING TWO METALS BY WORKING THEM TOGETHER IN A FORGE TO PRODUCE AN

OBJECT MORE USEFUL OR ARTISTIC THAN EITHER METAL ALONE IS AS OLD AS

METALWORKING HISTORY.

AND TODAY, THE USE OF BI-METAL COMBINATIONS ARE AS COMMON AS THE COINS

RATTLING IN OUR POCKETS.

BACK IN THE 1960’S, FACED WITH POTENTIAL SHORTAGES AND CERTAIN ESCALATING

PRICES FOR SILVER, THE U.S. MINT VENTURED INTO THE CLAD METAL BUSINESS.

ALMOST TWENTY YEARS LATER WE FIND THAT EVERY COIN ABOVE A NICKEL IS A

CUPRO-NICKEL — COPPER COMPOSITE. THE RESULT, AND THE HUNT BROTHERS NOTWITHSTANDING, IS A SUBSTANTIAL SAVINGS OF SILVER FOR THE GOVERNMENT.

TODAY, COMPOSITE METALS ARE PRODUCED IN A VARIETY OF COMBINATIONS AND

FORMS. THESE RANGE FROM APPLICATIONS AS COMMON AS COINS TO EXOTIC, ONEOF-A-KIND ELECTRONIC CONNECTORS USED ON THE SPACE SHUTTLE.

COMPOSITE METALS NOW ARE PRODUCED IN A VARIETY OF COMBINATIONS AND FORMS

WHICH ARE ESSENTIAL TO MODERN LIFE. INCLUDED ARE RIBBON, FOIL, TUBING,

PIPE, WIRE, INLAYS, SHEET, STRIP, AND PLATE — USED IN THE ELECTRICAL,

ELECTRONIC, SEMI CONDUCTOR INDUSTRIES; IN MEDICINE} IN COOKING UTENSILS

j

IN JEWELRY AND COINS; AND IN OUR PROCESS INDUSTRIES. INTEGRALLY BONDED

COMPOSITE SHEET, STRIP, AND PLATE ARE BEING PRODUCED BY COLD ROLLING,

HOT ROLLING, PRESSING, BRAZING, WELDING, ELECTROPLATING, SINTERING, OR

COMBINATIONS OF THESE METHODS.

P26-2
2

HOT ROLLED STEEL PLATE ACCOUNTS FOR THE GREATEST TONNAGE OF CLAD METAL

BEING MADE AND PROVIDES THE LARGEST OPPORTUNITY FOR CONSERVATION OF

SCARCE METALS. CLAD STEEL PLATE MAY BE DEFINED AS A COMPOSITE IN WHICH

THE TWO OR MORE METALS ARE 100 PERCENT METALLURGICALLY BONDED. THIS

DEFINITION EXCLUDES APPLICATION OF SHEET LININGS BY INTERMITTENT FUSION

OR SPOT WELDS; THOUGH, IN THE PAST, RESISTANCE SPOT WELDED COMPOSITE

PLATES MADE BY ONE LARGE PRESSURE VESSEL MANUFACTURER HAD NEARLY A

100 PERCENT BOND.

CLADDING OF STEEL PLATE HAD ITS BEGINNING IN THE LATE 1920’S WITH THE

DEMAND OF THE CHEMICAL INDUSTRY FOR LARGE NICKEL VESSELS TO CARRY CAUSTIC.

LUKENS DEVELOPED THE SANDWICH ROLLING METHOD, AND IN 1930 SOLD THE FIRST

NICKEL CLAD STEEL PLATE. THE PETROLEUM INDUSTRY AT ABOUT THE SAME PERIOD

WAS REALIZING THE NEED FOR STAINLESS STEEL FOR LARGE PROCESS VESSELS.

IN THE MID THIRTIES, ATTEMPTS WERE MADE TO BOND STAINLESS AND CARBON STEEL

PLATE BY ROLLING THEM WITH AN INTERLAYER OF INGOT IRON. THIS METHOD DID

NOT PRODUCE A SATISFACTORY BOND AND WAS SUCCEEDED BY THE PLURAMELT PROCESS

IN WHICH STAINLESS STEEL WAS FUSION WELDED VERTICALLY AGAINST A STEEL

SLAB, THEN HOT ROLLED TO PLATE. PLURAMELT PROVED TO BE UNECONOMICAL AND

WAS SUPPLANTED IN THE EARLY 1940’S BY A METHOD IN WHICH IRON WAS ELECTROPLATED ON THE STAINLESS. AN ASSEMBLY WAS THEN HOT ROLLED TO PLATE AS

LUKENS DID WITH NICKEL CLAD. THIS METHOD PRODUCED A STRONG BOND BUT ALSO

ALLOWED A LOT OF CARBON TO DIFFUSE IN THICK, HEAT TREATED PLATE. IN THE

MID FORTIES, LUKENS BEGAN TO PRODUCE STAINLESS CLAD STEEL PLATE BY ELECTROPLATING WITH NICKEL. THIS METHOD NOW IS USED BY MANY OTHER STEEL MILLS

AROUND THE WORLD.

P26-3
- 3 -

THE USE OF ELECTROPLATED NICKEL MAKES POSSIBLE A SOLID PHASE WELD DURING

THE HEATING AND ROLLING OF A WELDED "SANDWICH" BECAUSE IT AVOIDS OXIDATION

OF HIGH CHROMIUM ALLOYS WITHIN THE WELDED PACK. IT HAS THE FURTHER

ADVANTAGE OF RETARDING DIFFUSION OF CARBON FROM THE STEEL INTO THE STAINLESS

STEEL AFTER THE SURFACES HAVE BEEN WELDED TOGETHER. ROLLING WITH AN

INTERLAYER OF ELECTROPLATED NICKEL IS PRESENTLY USED TO MAKE INTEGRAL

BI-METALLIC PLATES WITH CLADDING METALS AS DIVERSE AS PURE COPPER AND

SUCH NICKEL BASE CHROMIUM MOLYBDENUM ALLOYS AS INCONEL 625. THESE TWO

MATERIALS REPRESENT EXTREMES IN HARDNESS AT STEEL ROLLING TEMPERATURES.

THE COMPATIBILITY OF HOT WORKING CHARACTERISTICS OF STEEL AND THE CLADDING

METAL ARE THE ONE FACTOR GOVERNING THE FEASIBILITY OF ROLL CLADDING.

ALUMINUM CAN BE, AND HAS BEEN, ROLL CLAD TO CARBON STEEL; BUT THE PROCEDURES

REQUIRED TO DO IT SUCCESSFULLY ARE NOT ECONOMICAL IN THE STEEL MILL.

SUCCESSFUL HOT ROLL BONDING OF COMPOSITES ALSO DEPEND UPON THE PROPERTIES

OF THE ALLOYS FORMED BY DIFFUSION AT THE INTERFACE. TITANIUM FORMS BRITTLE

INTERMETALLIC ALLOYS WITH NICKEL OR IRON AND IS NOT EASILY CLAD TO CARBON

STEEL IN THE MILL.

TWO OTHER METHODS FOR MANUFACTURING LARGE INTEGRALLY CLAD STEEL VESSELS

ARE IN WIDE USE TODAY AND EACH HAS ITS TECHNOLOGICAL AND ECONOMIC ADVANTAGES.

ONE OF THESE METHODS OF CLADDING IS FUSION WELD OVERLAY.

A GREAT MANY FABRICATORS HAVE THE EQUIPMENT AND KNOW-HOW FOR PRODUCING

ECONOMICAL OVERLAYS WHICH ARE PHYSICALLY SOUND AND CHEMICALLY AND METAL

LURGICALLY EQUAL TO WROUGHT ALLOYS IN SERVICEABILITY. PREDOMINANTLY, THE

METALS APPLIED TO CARBON STEEL BY WELD OVERLAYING ARE THE AUSTENITIC

STAINLESS ALLOYS; BUT WELD CLADDING OF CARBON STEEL CAN BE PERFORMED WITH

ANY METAL WHICH CAN BE DEPOSITED BY ARC WELDING — COPPER, COPPER BASE

ALLOYS, AND NICKEL BASE ALLOYS

P26-4
- 4 -

THE ECONOMY OF OVERLAY CLADDING — AS AGAINST PURCHASE OF MILL CLAD OR

EXPLOSION CLAD PLATE — DEPENDS UPON THE EFFICIENCY WITH WHICH THE

FABRICATOR IS ABLE TO DEPOSIT A METALLURGICALLY SUITABLE OVERLAY. WHAT

HE MUST DO IS TO ACHIEVE A HIGH DEPOSITION RATE WHILE MINIMIZING THE

AMOUNT OF BASE STEEL MELTED INTO THE CLADDING. FABRICATORS USE VARIOUS

MEANS OF DOING THIS. MOST LARGE-SCALE OVERLAYING IS DONE WITH THE SUBMERGED

ARC PROCESS. IN THE CASE OF STAINLESS STEEL, FLUXES WITH CR, NI, AND MO

REINFORCEMENT ARE AVAILABLE TO COMPENSATE FOR IRON PICKUP; BUT EVEN SO,

ARC ENERGY MUST BE CONTROLLED TO LIMIT CARBON CONTENT IN THE CLADDING.

SO THE FABRICATOR'S BASIC PROBLEM IS TO ACHIEVE HIGH DEPOSITION RATE WITH

LOW PENETRATION. VARIOUS TECHNIQUES TO DO THIS ARE AVAILABLE. A COLD

WIRE CAN BE FED INTO THE ARC, SERIES ARC CONNECTION, OR STRAIGHT POLARITY

CAN BE USED. MOSTLY WHAT IS DONE IS TO USE LOW ARC ENERGY INPUTS AND TO

INCREASE THE NUMBER OF ARCS BY USING THREE OR EVEN SIX WIRE ELECTRODES

SIMULTANEOUSLY. ANOTHER SYSTEM IS TO USE A METAL STRIP INSTEAD OF WIRE

ELECTRODES. THEN THE ARC OF REDUCED INTENSITY TRAVELS ALONG THE STRIP

KEEPING PENETRATION DOWN BUT MAINTAINING HIGH DEPOSITION RATE. COMPOSITE

WIRES ARE COMMONLY USED FOR WELD CLADDING. THESE ARE TUBES WHICH CONTAIN

THE ALLOYS DESIRED IN THE OVERLAY. SUCH ELECTRODES OFFER FLEXIBILITY IN

ALLOY SELECTION AND ALSO GIVE AN ARC OF REDUCED PENETRATING FORCE. COMPOSITE

ELECTRODES CONTAINING FLUX ARE AVAILABLE FOR OPEN-ARC WELDING.

IN 1964 A THIRD METHOD OF PRODUCING LARGE CLAD PLATES BECAME AVAILABLE TO

INDUSTRY. AFTER MANY YEARS OF RESEARCH ON PHENOMENOLOGICAL THEORY AND

DEVELOPMENT OF PRACTICE, DUPONT OPENED A PLANT FOR CLADDING METALS BY THE

USE OF A CONTROLLED EXPLOSION. ESSENTIALLY, TWO OR MORE METAL SURFACES

ARE FIXED PARALLEL AND SLIGHTLY APART. AN EXPLOSIVE CHARGE CAUSES A

PROGRESSIVE ANGULAR COLLISION BETWEEN THE CLADDING METAL AND THE SUBSTRATE.

THE FORCE OF THE COLLISION PRODUCES A JET OF METAL WHICH SWEEPS AWAY SURFACE

P26-5
- 5 -

CONTAMINANTS AND CAUSES A SOLID PHASE WELD TO BE MADE UNDER THE DETONATION

FRONT. THE EXPLOSION WELDED INTERFACE IS A PATTERN OF REGULAR WAVES

CREATED BY PLASTIC FLOW. A SMALL AMOUNT OF MELTING MAY OCCUR; IN WHICH

CASE THE MELTED METAL IS ENCASED BY DUCTILE MATERIAL IN THE TROUGH OF THE

WAVES

BECAUSE EXPLOSION BONDING IS DONE COLD AND IS ESSENTIALLY DIFFUSIONLESS,

THE PROCESS IS ADMIRABLY SUITED TO JOINING METALS WHICH ARE REACTIVE AND

WHICH FORM BRITTLE INTERMETALLICS SUCH AS TITANIUM STEEL, ALUMINUM/ STEEL

IT IS ALSO CAPABLE OF BONDING MORE THAN TWO DIFFERENT METALS SIMULTANEOUSLY

AND OF CLADDING METALS WHICH ARE VASTLY DIFFERENT IN MELTING POINTS AND

MECHANICAL CHARACTERISTICS SUCH AS TANTALUM/COPPER/ STEEL . AS IS TRUE OF

THE OTHER CLADDING PROCESSES, THERE ARE PREREQUISITES FOR SUCCESSFUL

EXPLOSION BONDING. A CERTAIN AMOUNT OF DUCTILITY IS REQUIRED OF THE

CLADDING METAL AND THE SUBSTRATE MUST POSSESS ENOUGH FRACTURE TOUGHNESS

TO RESIST THE IMPACT LOADING OF THE EXPLOSION. METALS OVER 100 KSI YIELD

STRENGTH ARE NOT EASILY CLAD BY THE EXPLOSION PROCESS.

THE CAPACITY FOR INCREASE IN PRODUCTION OF CLAD BY ALL THREE METHODS IS

VERY LARGE AS IS THE POTENTIAL FOR DEVELOPMENT OF CLAD COMBINATIONS AND

METHODS NOT NOW IN USE.

THERE ARE SOME ENGINEERING APPLICATIONS FOR WHICH COMPOSITE PLATE AND

ONLY COMPOSITE PLATE IS SUITABLE; BUT IN GENERAL, CLAD PLATE IS USED

WHERE IT IS AN ECONOMICAL SUBSTITUTE FOR THE ROMOGENEOUS METAL REQUIRED

FOR THE INTENDED USE. THE RATIO OF FINISHED PRICE OF A CLAD STEEL VESSEL

TO THE PRICE OF THE HOMOGENEOUS ALLOY VESSEL IS GREATER THAN THE RATIO OF

CLADDING. FOR THIS REASON, CLAD STEEL IS USED ONLY WHERE CORROSION RATES

ARE LOW. THE MORE EXPENSIVE THE ALLOY, HOWEVER, THE MORE FAVORABLE WILL

BE THE PRICE OF THE CLAD PLATE. OF COURSE, THE PRICE OF A COMPLETED VESSEL

P26-6
- 6 -

DEPENDS UPON FABRICATION AS WELL AS CLAD COSTS. THIN CLAD PLATES ARE

LIKELY TO COST SOMEWHAT MORE TO FABRICATE THAN WOULD AN ALL-ALLOY PLATE;

BUT AS THICKNESS INCREASES, SAVING OF ALLOY WELD METAL INCREASES. AGAIN,

THE MORE EXPENSIVE THE ALLOY, THE GREATER THE SAVING.

IT IS SAFE TO SAY THAT THE EXTENT OF CURRENT USAGE OF CLAD PLATE AS A

SUBSTITUTE FOR ALL-ALLOY PLATE IS DICTATED PRIMARILY BY THE RELATIVE

COSTS OF THE TWO PRODUCTS RATHER THAN BY TECHNOLOGICAL CONSIDERATIONS.

TO PUT IT ANOTHER WAY, A LOT OF CHROMIUM WHICH WILL NEVER SEE A CORROSIVE

ENVIRONMENT IS BEING USED TO PROVIDE SUPPORT IN TANKS AND TO RETAIN

PRESSURE IN VESSELS.

PERHAPS EVEN MORE IMPORTANTLY, WHEN MAKING LONG-RANGE PLANS THERE WILL BE

OTHER FACTORS WHICH BEAR CONSIDERATION. ALL OF US WHO STRUGGLED THROUGH THE

PAST TWO OIL CRISES ARE AWARE OF THE CONSEQUENCES OF UNSTABLE SUPPLY SOURCES.

WE ALL SAW SHORT RUN PURCHASE CRITERIA SUCH AS PRICE BEING DISCARDED THE

MOMENT AVAILABILITY BECAME THREATENED. IN THE LONG RUN, CAN’T IT BE SAID

THAT WE ARE FACING THE SAME TYPE OF PROBLEM IN STRATEGIC MATERIALS?

AND THEN WOULDN’T IT FOLLOW THAT PRAGMATIC CONSERVATION PRACTICED BEFORE

THE FACT COULD HELP FORESTALL OR BLUNT THE IMPACT OF SIMILAR MATERIAL CUTOFFS?

THE POINT IS, PRICE HAS ALWAYS BEEN A SHORT RUN FACTOR. IN 1981 WE CANNOT

ONLY AFFORD TO BE CONCERNED WITH JUST SHORT RUN FACTORS.

AND CLAD METALS, BE THEY ROLL OR EXPLOSIVE BONDED OR WELD OVERLAY, DO OFFER

A VIABLE ALTERNATIVE TO' SOLID ALLOYS WITH BOTH SHORT AND, MORE ESPECIALLY,

LONG RUN ADVANTAGES.

PRESENTATION BY

JAMES M. GLAZEBROOK

MANAGER, HEAD AND CLAD SALES

LUKENS STEEL COMPANY

P26-7
CONSERVATION OF CRITICAL METALS UTILIZING SURFACE ALLOYING

Ray J, Van Thvne

Dilex Systems

P27
CONSERVATION OF CRITICAL METALS UTILIZING SURFACE ALLOYING

Ray J. Van Thyne*

Summary

Surface alloying offers a significant opportunity for conserving chromium and other critical metals. Surface alloying is discussed generally and the Dilex process for surface

alloying of ferrous products in a molten lead medium is described. The Dilex process offers technical and economic advantages, and the opportunity to produce unique materials.

A wide range of materials offering resistance to corrosion,

oxidation, and wear have been produced.

* Dilex Systems, Material Sciences Corporation,

1909 S. Busse Road, Mount Prospect, 111. 60056 (312) 437-9855

P27-1
CONSERVATION OF CRITICAL METALS UTILIZING SURFACE ALLOYING

I . Introduction

Surface alloying offers a significant opportunity for conserving

critical metals such as chromium. Elements are utilized in the

most effective manner by placing them on the surface where they

are required for corrosion, oxidation or wear resistance. Surface alloying may be accomplished by various means such as high

temperature diffusion, selected surface melting or ion implantation. The former is the most common.

This paper will describe several methods of surface alloying but

will focus on the Dilex process which involves diffusion alloying, principally of ferrous products in a high temperature lead

medium.

P27-2
II. CONSERVATION OF CHROMIUM AND OTHER CRITICAL METALS

It is obvious that replacing solid stainless steel with chromized or other surface alloyed products results in considerable reduction in usage of chromium. In typical small fabricated parts, a 3 mil chromized surface layer accounts for only

about 6% of the total volume of the part. In chromized steel

sheet with a 3 mil layer on both sides of a 40 mil sheet 15%

of the cross-section is stainless steel.

Although the average chromium content of the chromized layer

is somewhat higher than in homogeneous stainless steel (23%

versus 18% typically), chromium savings are over 80%. Surface

alloying offers opportunities for further savings in chromium

by multiple alloying, i.e., replacement of part of the chromium

content by aluminum in an oxidation resistant material, or

conservation of other alloying elements by use of other surface alloyed steel or stainless steel to replace more premium

materials

Chromized steel is a candidate substitute for homogeneous

stainless steel in many applications. Corrosion and oxidation

resistance are surface properties and the material need have

these properties only for some finite practical distance in

from the surface to provide a reservoir of alloyed material

and to provide for scratch and abrasion resistance. Although

platings and other coatings have been considered as substitutes

P27-3
for bulk stainless steel, they have met with limited success

since they do not have the required surface properties and are

prone to coating defects. Such coatings generally have poor

mechanical properties, are not well bonded to the substrate,

and will delaminate or crack during forming. The formability

of surface diffusion alloyed mild steel is similar to, and in

many cases better than, stainless steel. For sheet applications

the exposed cut edge must be accommodated through design or

fabrication. Stainless steel welding techniques are successfully used. Surface alloyed mild steel has lower strength than

stainless steel which will limit its use in applications requiring higher strength at ambient or elevated temperatures.

The substitution of surface diffusion alloy products for homogeneous stainless steel has been very limited to date. Further

expansion of this market will depend upon additional developmental

work, pilot production to supply limited quantities of material

to potential users to develop fabrication and application experience, and capital investment to produce certain products.

This is a relatively long process since field tests often require one year.

P27-4
III. SURFACE ALLOYING PROCESSES

Surface alloying is generally used because of cost effectiveness or the ability to produce special properties or composite

materials. Selected composite properties of interest are

shown in Table I. Some of the processes available are given in

Table II. Materials are exposed to a wide range of hostile environments experienced in such applications as petrochemical,

coal gasification, chemical spray nozzles, marine, and various

consumer products. Chromizing is the surface alloying process

that has received the greatest attention and a diffusion curve

is shown in Figure 1

Typical commercial applications of surface alloying include

coated gas turbine hardware for oxidation resistance, and aluminized tubing in petrochemical heat exchangers for sulfidation -

and oxidation-resistance. Pack chromizing of parts is being

performed on a limited basis. Chromized steel sheet produced

by rolling of ferrochrome powder on the surface of steel followed by diffusion annealing was commercially available until

recently. The largest single use of this material was in gasfired heat exchangers inf commercial furnaces. The chromized

steel was preferred to stainless steel because of its superior

corrosion resistance resulting from the higher surface chromium

content, and the material provided a manufacturing advantage

compared to stainless steel of less spring-back in forming.

A number of metal treating techniques are available using ion

processing including ion implantation. This is in the development

P27-5
TABLE I

COMPOSITE PROPERTIES BY SURFACE ALLOYING

Corrosion Resistance + Thermal

Different Surfaces on Tubes

Corrosion Resistance + Magnetic

Corrosion/Oxidation + Fabricability

Ferritic/Austenitic Avoid Stress-Corrosion

P27-6
TABLE II

SURFACE ALLOYING METHODS

PACK CHROMIZING, ALUMINIZING, BORONIZING

GAS TRANSPORT

DEPOSIT FERROCHROME POWDER AND DIFFUSE

LASER, PLASMA TORCH, ION IMPLANTATION

SALT BATH CONTROLLED DEPOSITION

DILEX LIQUID METAL TRANSFER

P27-7
*3

’

m

CM

+-» a

<v a

\ on

oCM

iuniiiicuq3 %

P27-8

Figure

1

Chromium

Diffusion

Into

Iron
stage and involves a plasma of ions driven by an electrical

charge. The resultant surface alloy is extremely thin and in

the range of 500 to 3000 K. Implantation of chromium has been

considered for improving corrosion of aircraft bearings during

shelf storage prior to use. A major advantage is that the substrate remains cool during processing.

Although laser drilling, welding, and heat treatment is commercial, laser alloying is generally in the development stage. It

offers opportunities for good control, selected area treating,

and limited heating of the substrate. Chromium and aluminum

have been alloyed into ferrous surfaces and carbide has been

fused into the surface of aluminum. In layerglazing, a thin

layer of the substrate is melted with an alloy addition and extremely rapidly self-quenched . Also Stellite 6 has been laser

clad on steel with only limited interalloying.

Wear resistant surfaces are produced by pack or salt bath boronizing. Metal carbides are formed by reaction of infusing

metals and carbon in the steel.

P27-9
IV. DILEX PROCESS

The Dilex process involves diffusion surface alloying principally of ferrous products in a lead medium and offers advantages over alternative processes. A wide range of useful elements shown in Table III may be controllably transferred. The

elements are listed in descending order of dependency on imports. Constituents that cannot be diffusion treated may be

prealloyed into the substrate. Multi-alloying by co-diffusion

has been demonstrated. Unique materials of a composition and

form that would be very difficult to make by other metallurgical processing methods have been produced. The molten lead

readily contacts all surfaces and is a highly efficient alloy

transport medium thus resulting in very uniform alloying, and

intricate shapes may be processed .

In the principal step of the process, the ferrous product is

immersed in lead within a retort and alloying additions such as

f errochromium are included in a screened cage. Lead melts at

620° F and typical processing temperatures are 1850° F to 2050°.

Surface alloying occurs by simple metallic diffusion; no chemical or electrochemical processes are involved. Molten lead

is an ideal medium and exhibits a number of useful properties

for this application as follows:

1. Inexpensive and readily available

2. Reuseable and refined by skimming off impurities that float to the surface.

P27-10
TABLE III

TRANSFERRED BY DILEX PROCESS

MANGANESE

COBALT

CHROMIUM

NICKEL

TITANIUM

ALUMINUM

P27-11
3 . Rapid heating and cooling because of the

high heat transfer with relatively low enerby consumption (the specific heat of lead is

about one-third that of steel)

4. Low vapor pressure of molten lead allows it

to be readily handled in the open at temperatures of 800°F and negligible pressurization

occurs in sealed retorts since the vapor pressure is less than 0.1 psi at 2000°F

5. A molten metal medium facilitates continuous

processing if desired

6. Compatible with steel and stainless steel

since the solubility of iron in molten lead is

about 0.01% at 2000°F

7. Lead is insoluble in steel

8. Solute transfer through the molten lead is rapid

even though alloying solubilities may be low;

for example, the solubility of chromium is 0.05%

at 2000°F. An excess of chromium may be used with

the chromium dissolving into the bath as required

9. The only processing controls are temperature and

time if excess alloying additions are used

10.

After processing, lead is readily removed from

the treated product by mechanical , chemical dissolution and/or de-wetting procedures

P27-12
11. Multiple alloyed products can be produced

Chromizing at 2050°F for four hours produces a 0.004 inch thick

stainless steel layer and requires a total batch processing

cycle time of about 20 hours. The lead holding retorts are

electrical radiant heated and are constructed of type 304 stainless steel with an outer shell of Inconel 617 over the bottom

portion for increased high temperature oxidation resistance and

strength. Retorts are only opened at temperatures below 1000°F

and are sealed under an inert gas at more elevated temperatures.

A periodic vertical motion is imparted to the load, which is accomplished by a drive shaft through the cover. Retorts up to

33 inches in diameter shown in Figure 2 have been operated.

Components that have been treated on a developmental basis include: open wrapped coil, foil, fabricated components, short

length tubing, and a variety of small machined, cold headed, or

PM parts. The small parts are fixtured (Figure 3) or treated

loosely, depending upon the requirements. With loose parts,

some relative motion, such as by agitation must be provided

about every 5 minutes to avoid bonding. Only batch processing

has been employed to date, but continuous throughput processing

is feasible.

To achieve excellent corrosion resistance with simple chromizing,

interstitial element control of the steel is necessary. Free

carbon in the steel will react with infusing chromium causing

sensitization. Accordingly, a steel with negligible carbon or

a special substrate steel is required. One steel that has been

successfully treated is commercially available IF steel (0.01 C,

P27-13
Figure 2 Dilex Reactor

P27-14
Figure 3

Fixtured Parts for

Dilex Processing

Figure 4

Dilex chromized part, sectioned

and etched to show the uniformity of the Dilex layer X 1.5

P27-15
0.03 Al, 0.04 Ti, 0.04 Cb) . Current work on Dilex co-alloying

may allow a broader range of steels to be accommodated.

The Dilex surface alloy layer is extremely uniform as shown in

Figure 4. This is a sample sectioned after chromizing and immersing in boiling nitric acid which attacks any composition

lower than 12% chromium. The sharply defined boundary seen in

the sample is a chemical rather than a physical boundary. The

surface layer is not a coating as Figure 4 might indicate and

cannot delaminate from the substrate. Semi-tubular rivets

treated by the Dilex process withstand setting of 90° without

damage to the alloyed layer. The uniformity of the Dilex chromized layer on sheet is illustrated in Figure 5. Densif ication

of the outer layer occurs during surface alloying of PM materials

(Figure 6) . A growth of about one mil accurs with a 5 mil Dilex

chromized layer.

Certain parts that would be difficult or impossible to cold head

from solid stainless steel may be made from low carbon steel and

then treated by the Dilex process. Cost savings up to 25% may be

achieved in Dilex treatment of various low carbon steel parts made

on screw machines, compared to stainless steel. Although some

material savings result, the principal advantage is the substantial reduction in machining costs. However, the inclusions present in free machining steel degrade the corrosion resistance.

Small experimental batches of low carbon steel wire have been

chromized by the Dilex process. This wire was cold drawn to

92% reduction in area without any crabking or delamination.

This cold worked wire exhibited a tensile strength of 90,000 to

P27-16
>-v

F 1 a are 6

Dilex chromized PM showing

dens ificat ion. Nital

etch x 125

P27-17
100,000 pounds per square inch with 7% elongation. This

strength is low compared to cold drawn stainless steel wire.

Dilex treated wire drawn to 76% reduction in area exhibits

strength similar to wire drawn to 92% reduction in area. Salt

water immersion tests of 100 hour duration were performed on

the wire after 76% cold reduction in area. No rust spots were

evident after testing, which demonstrates the integrity of the

Dilex layer. Wire would be processed on a continuous throughput process using multiple strands.

Many 1000 pound coils 24 inches wide have been produced on a developmental basis. These were processed as open wrapped coils,

and it has been demonstrated that the lead medium provides uniform surface alloying even with very narrow spacing between the

circumferential wraps. A two strand twisted wire inserted into

each edge of the coil during wrapping provided a 0.090 inch

spacing. The sheet operations are schematically illustrated in

Figure 7, and a processed coil is shown in Figure 8. A heat

shield is located above the coil, and a single screened cage

for holding the alloy charge is on the bottom.

The substrate was IF steel. The final thickness may range from

6 to 100. mils. Generally, the steel coils were treated by the

Dilex process, cold rolled, annealed, and temper rolled. The

steel sheet was treated to yield a thicker initial layer and

provide a 3 mil final thickness after fabrication. A 0.007 inch

thick' chromized layer which would be cold rolled 50% is produced

in 12 hours at 2050°F and requires a total processing cycle time

P27-18
P27-19

DILEX

DIFFUSION

ALLOYING

SHEET

OPERATIONS
P27-20
of 30 hours. The corrosion properties were competitive with

type 430 SS. The mechanical properties were reduced compared

to stainless steel. Sheet material in the temper rolled condition with an ASTM grain size of 6 has typical properties of

43,000 psi tensile strength, 28,000 psi yield strength, and 35%

elongation. Higher strengths can be achieved by greater amounts

of residual cold working. The formability of the material is

excellent as evidenced by a 2 inch diameter cupping test and a

6 inch box made from a 12 inch diameter blank shown in Figure 9.

Batch treated Dilex chromized open wrapped coil does not presently offer cost savings over the cheaper grades of stainless steel;

the projected Dilex processing cost is about $0.30 per pound of

20 gage (0.036 inch thick) sheet based upon processing of 20,000

pound coils and production of 10,000 tons per year. This cost

does not include the starting steel or cold rolling after Dilex

treatment

The Dilex processed surface is smooth. Even though substantial

material is added through surface alloying, fine details such as

scratches from machining are replicated. The resultant surface

finish as Dilex processed is about 80 rms , which is equivalent

to a machined surface. For sheet applications, the exposed cut

edge must be accommodated through design or fabrication methods.

The generation of special alloys and structural shapes are important parts of the Dilex technology. As shown in Figure 10,

an Fe-Cr-Al surface alloy is produced. It has excellent oxidation resistance to 1700°F. By regulation of the aluminum addition, the level can be controlled over the range of 0 to 25% to

P27-21
Figure 9 Formability Tests on Dilex

Chromized Steel Sheet

P27-22
00

CM O CO CO

CO CO CM CM

*3

" CM

CM

CM OCM

CO CO CM CO VO CM

(}uao Jdd ;q6t9M) NOUISOdWOO

P 27-23

DISTANCE

FROM

SURFACE

(thousandths

of

an

inch)

Figure

10

CONCENTRATION

-

PENETRATION

CURVE

FOR

STEEL

SHEET

CO-ALLOYED

WITH

CHROMIUM

AND

ALUMINUM

GY

THE

DILEX

PROCESS
yield a desired combination of properties. Various other alloying elements may be employed to diffusion alloy steel or

up-grade type 430 or 304 stainless steel to compete with more

premium materials. In many corrosion applications, the lower

strength of the surface alloyed materials will not be a problem.

Various structural shapes have been treated by the Dilex process. Heat regenerator structures made of 2 mil corrugated

steel foil 3 inches thick have been through-alloyed to produce

typical compositions of Fe-22Cr-4Al. During processing, bonding occurs at all nodes where contact occurs as shown in Figure

11 .

Alloying constituents that are transferred in the Dilex process

may also be removed from the ferrous surface. By removing nickel

and/or adding chromium, a ferritic layer is produced on type

304 stainless steel than is more resistant to stress corrosion.

This has been confirmed by U-bend tests in boiling 42% magnesium

chloride. The test was terminated after 690 minutes; the untreated type 304 stainless steel showed serious cracking (Figure

12), but the Dilex treated material exhibited no cracking.

Two mil thick foil has been through-alloyed. In this manner

highly alloyed compositions may be made at or near final gage.

Equivalent compositions produced by conventional practices would

be extremely difficult to fabricate.

P27-24
Figure 11

Two mil foil corrugated

structure illustrating

through-alloying and bonding. Metal etch X 70

Figure 12

Samples illustrating stresscorrosion cracking in 304

stainless steel and no

cracking in Dilex treated

304 stainless steel.

P27-25
IV. WEAR RESISTANT MATERIALS

Surface alloying offers the opportunity of producing hard wear

resistant materials, and various methods may be used. When

steels containing over 0.30 percent carbon are chromized, a continuous chromium carbide layer, typically up to 1 mil thick,

is formed. This layer has a hardness of about 1800 DPN (50 g

load) which is about twice that of hard chromium plate and about

equal to that of commercial tungsten carbide. The chromium carbide layer that is formed will allow subsequent heat treatment

of the steel without spalling. The combination of a high hardness layer backed up by a hardened tough steel is desirable.

Preliminary evaluations include a forming punch and erosion resistant nozzles. Dilex processing offers the possibility of

producing other carbides having higher hardness than chromium

carbide, such as titanium carbide or mixed carbides.

P27-26
ELECTRON BEAM IRRADIATION APPLIED

TO CONSERVATION OF CRITICAL MATERIALS

Joe E. Jenkins

Leybold-Heraeus Vacuum Systems Inc.

P28

ELECTRON BEAM IRRADIATION

APPLIED TO

CONSERVATION OF CRITICAL MATERIALS

Paper prepared for the

"Workshop on Conservation and Substitution

Technology for Critical Materials"

15-17 June 1981

VANDERBILT UNIVERSITY

Nashville, Tenn.

By

Joe E. Jenkins

Senior Metallurgist

LEYBOLD-HERAEUS VACUUM SYSTEMS INC.

Enfield, CT

P28-1
Conservation of critical materials by irradiation with an

electron beam may be accomplished in several ways. Among these

is rapid surface fusion to refine the grains in metals and

alloys . A rapid surface fusion can result in subsequent high

solidification rates, the benefits of which are now being extolled in the technical press and at conferences. Strutt,

Nowotny, Tuli & Rear have reported on laser processing, and

Strutt and the Writer have reported on electron beam processing, References 1, 2, and 3.

Depending upon the alloy being treated and the specific

process parameters, a high degree of grain refinement with

metastable solid solutions is likely. In the case of steel

and cast iron, an extraordinarily high hardness level is obtained that is relatively insensitive to cracking.

Wear resistance is a materials property that is difficult

to measure with accelerated laboratory tests. Hardness has

been used as a basis for estimating the relative wear resistance

by designers. This is a convenient measurement to make in estimating the effect a rapid surface fusion may have on wear properties .

P28-2
2

AISI 1045, 4150, and 1090 steels have recently been

electron beam glazed in our laboratory. In each instance,

an extraordinarily high hardness level is obtained. Figure

1 compares the hardness due to glazing with that from conventional quenching. Note that the glazed hardness exceeds HRC

65 for all materials. We believe this high order of hardness

is useful because the glazed layer appears to have some toughness. Figure 2 shows adjacent, superimposed and edge microhardness indentations with no indication of cracking in AISI

4150 steel at HRC 67. Glazing may eliminate the need for

expensive, critical materials to develop hard wear resistant

surfaces in certain practical applications.

Aluminum alloys also respond to glazing. Figure 3 is a

photomicrograph of a section taken through a path glazed with

a high power electron beam in Alloy 319. The glazed material

is on the left in the micrograph. This was done with the

alloy at atmospheric pressure by use of the non-vacuum electron

beam process. The solidification rate was adequate to afford

a high degree of refinement in the grain structure. Microhardness tests show the glazed layer to be HVN 111 and the

untreated material to be HVN 78. This is enough increase to

permit an auto engine part to function with no inserted wear

pad.

P28-3
3

We are developing successful application of electron

beam glazing on a diesel engine part made from modular iron.

Direct high rate surface fusion has replaced cobalt base and/

or high chromium hard facing in experimental parts . Figure 4

shows two views of a treated part. The fusion is explicit.

Treatment time was two seconds.

Figure 5 shows a longitudinal section of a similar part

processed by hard-facing, and one electron beam glazed. The

savings in critical alloys is obvious. In addition, it appears

that the reject rate can be reduced, as subsequent spot hardening treatment causes some cracking at the hardfacing interface.

The time to finish grind can either be eliminated, or reduced

to a small percentage of that currently required. EB processed

parts are being engine tested "as treated" as well as with a

light post glaze grind. In either event, appreciable process

time, finish time and critical alloy is saved.

Figure 6 is a plot of microhardness survey data taken on

a section after treatment. Superimposed on this plot is a

photomicrograph of a section taken through a glazed area.

Note the extreme hardness of the refused layer which extends

to a depth of 3/4 of a millimeter. Under this layer, a layer

of white iron is developed having slightly less hardness, to

a total depth of 1.5 millimeters.

P28-4
4

Figure 7 is a photomicrograph of the fusion - white

cast iron transition. The recast layer (at the top) consists

of a fine cementite (Fe 3 C) dendritic structure in an austenitic

matrix hardened by precipitation of Fe3 C and perhaps some

graphite. These structure details measure HVN 800-1100 (equivalent HRC 64-70X) . These microhardness data were obtained with

a 25 gram load.

In engine tests, these electron beam treated parts are

doing well at last report, and are well on the way toward a

10,000 hour test objective.

Savings in chromium, vanadium, tungsten, and molybdenum

are effected through discrete use of high speed steel. Electron beam welding permits just the teeth of band saw blades,

among others, to be high speed steel with the blade body made

of low alloy steel. Figure 8 shows a piece of welded band saw

blade stock.

Figure 9 is a photomicrograph of a section through this

stock. The weld is approximately 0.25 mm wide, and is made

at speeds up to 18 meters /minute . Approximately 95% savings

in high speed steel is effected, with an improvement in

quality

P28-5
5

This bi-metal idea has been used in production since 1968.

However, accelerated use of this electron beam welding technique

has been experienced in recent years due to the increasing cost

differential of the tool steel and the increase in modern equipment which is 2 to 3 times more productive than the earlier systems .

This same philosophy is being persued with thicker, more

massive cutters. Tools having welds up to 20 mm deep have

been made successfully in the laboratory. Several applications

are pending.

Surface modification through electron beam glazing and

discrete use of high alloy through electron beam welding have

saved thousands of tons of critical material and hold promise

of effecting savings at an increasing rate in the future.

P28-6
REFERENCES

1.

P. R. Strutt, H. Nowotny, M. Tuli & B . H. Rear

Materials Science 6c Engineering 36 (1978) 217.

2. P. R. Strutt, Materials Science 6c Engineering

44 (1980) 239.

3. J. E. Jenkins, International Conference on

Metallurgical Coatings, Abstract Book P10, San

Francisco, 1981.

P28-7
HARDNESS, HRC

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LOO

4^O

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'-J O

OT

P?8-3

GLAZED

HARDNESS

COMPARED

WITH

QUENCHED

HARDNES
600X

Superimposed Hardness Tests

In Glazed Layer AISI 4150 Steel

FIGURE 2

Glazed Parent Metal

Glaze Transition

Aluminum Alloy No. 319

FIGURE 3

P28-9
E. B. Glazed Engine Part

FIGURE 4

Longitudinal Sections of

Hard Faced Part (Top) 6c E . B

Glazed Part

FIGURE 5

P28-10
HARDNESS

in

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FIGURE 6
Glazed

Glaze Transition

"White" Nodular

Cast Iron

30 OX

Glazing Transition

FIGURE 7

P28-12
Weld Face Root

E.B. Welded Saw Blade Stock

FIGURE 8

Cross Section Through Weld

FIGURE 9

P28-13
APPLICATION OF THERMAL SPRAYING PROCESSES

TO CONSERVE CRITICAL MATERIALS

Edward R. Novinski

METCO Inc.

P29
APPLICATION OF THE THERMAL SPRAYING

PROCESSES TO CONSERVE CRITICAL MATERIALS

Edward R. Novinski

METCO INC.

BACKGROUND

Over the past decade, the United States has seen the head-on effects of

the national crisis in energy and the environment. Both have markly commanded

public attention and have resulted in economic and social realignment. The

growing problem of material shortages is rapidly becoming the nation's next

challenge. The United States has an enormous appetite for both energy and

materials. With only six percent of the world's population, we consume 30% of

its energy.

^Materials consumption is more difficult to assess. However,

the United States chromium ore utilization in 1977 represented 25% of all world

production.

^The supply of critical metals and minerals is heavily dependent

on political and economic factors set by foreign sources. The long range supply

problems of metals center around chromium, cobalt, manganese , aluminum, and the

platinum' group. The United States relies on foreign import for 90% of these

materials . &) Suggested approaches to this crisis are in the development of

0 internail mineral reserves, government stockpiling, and materials conservation

and substitution. Of these, the most practical and readily instituted are

conservation and substitution. Over the last few years technology has made

-available many methods to permit use of less critical bulk materials. A major

example is in the area of surfacing techniques.

RESOURCE CONSERVATION BY THERMAL SPRAY COATINGS

Modern thermal spray coatings technology offers an immediate , proven

solution to critical materails conservation. An enormous amount of critical

bulk materails are annually lost through forms of wear and corrosion. Conservation of critical materials lost by these phenomena can be effectively achieved

P29-1
- 2 -

by shifting from bulk fabrication of high alloy components to lower cost, less scarce base metals combined with surface coatings. Materials conserva- tion through the use of thermal spray coatings allows several major advantages:

1. Scarce materials sure limited to the surface.

2. Coating thickness can be designed with regard to the service

life required.

3. Coatings are applied to the surface in areas only where needed.

4. Worn components can be restored by coatings to original dimension.

5. Coatings allow downtime to be cut relative to procuring new parts.

6. Maintenance costs are reduced due to greatly prolonged part service

life.

Thermal Spray Methods

Of the available modem surfacing methods, the thermal spray process is by far the most versatile with regard to economics, range of materials, and

applications. Thermal spray is a proven process with enormous potential for immediately reducing the need for critical materials and lowering manufacturing

and maintenance costs. The thermal spray coating process permits rapid application of high performance materials from a few mils in thickness to over one inch on parts with complex geometries. The process requires minimum base metal

preparation, can be applied in the field, and is a low temperature method in constrast to techniques such as weld' overlay.

All thermal spray processes rely on three basic mehcanisms: heating a coating material to a molten or plastic state, propulsion of the material, and impact of the material onto a workpiece resulting in rapid solidification. The

coatings are subsequently machined or ground using conventional equipment or in some cases can be used in the as-coated condition. Five principle thermal spray systems are commercially available: combustion wire process, combustion powder

P29-2
- 3 -

process , plasma deposition, detonation, and the arc wire process. System

eelection is determined by desired coating materials, coating performance

and overall economics. Each system readily lends itself to field applications with the exception of the detonation process which is restricted to complex laboratory applications.

Combustion Wire Metallizing

The combustion wire process is the oldest of the thermal spray coating methods and among the lowest in capital investment. The process utilizes an oxygen/fuel gas flame as a heating source and

coa,ting material in wire form. During operation the wire is drawn

into the flame by drive rolls that are powered by an adjustable air

turbine. The tip of the wire is melted as it enters the flame and is both atomized into particles by a jet of compressed air and propelled

to the workpiece. A variation of this process utilizes spray material

as ceramic rods for oxide coatings but for the most part this method

has been replaced by the combustion powder and plasma spray processes. Spray rates for the combustion wire process range from 5 to 120 lbs/hr

and are dictated by the melting point of the material and the choice

of fuel gas. The wire spray gun is most commonly used as a hand held

^device for on-site application although an electric motor driven gun is recommended for fixed mounted use in high volume, repetitive production

work. The combustion wire process finds wide use in corrosion protection

of large outdoor structures such as bridges and storage tanks and in restoration of dimension to worn machinery components. In general, the wire spray process is a good choice with regard to capital investment,

ease of set up , and minimum operator training.

P29-3
- 4 -

Combustion Powder - Thermospray

Another commonly used thermal spray coating method is the combustion

powder spray process. This method greatly extends the range of available

coatings and subsequent applications relative to the wire process to include oxides, ceramics, cermets, carbides, and hardfacing materials. In

this process powdered coating material is fed from a reservoir into a

stream of carrier gas. Here the material is both melted and propelled to

the workpiece by the flame and no atomizing stream is necessary as in the

wire process. Combustion powder guns are the lowest cost thermal spray

equipment, easiest to set up and change materials, and offer a wide range

of coating materials.

Plasma

Among the most sophisticated and versatile thermal spray methods is

the plasma spray system. Temperatures that can be obtained with commercial

plasma equipment have been calculated to be greater than 20,000# F and are

far' above the melting, or even the vaporization point of any know material.

Decomposition of materials during spraying is avoided since very high gas

velocities are produced by the plasma and therefore result in extremely

short residence time in the thermal environment. Additional advantages of

the plasma process is that it provides a controlled atmosphere for melting

and transport of the coating material thus minimizing oxidation and the

high gas velocities give rise to coatings of near theoretical density. The

plasma gun operates on the principle of raising the energy state of a gas

by passing it through an electric arc. The release of energy in returning

the gas to its ground state results in exceedingly high temperatures. A

gas such as nitrogen enters a direct current arc between a tungsten cathode

and a copper anode that makes up the nozzle. Both components are cooled

by a constant flow of water through internal passages. Here the nitrogen

P29-4
- 5 -

gas first dissociates into two atoms followed by ionization releasing

free electrons. It is this mixed region that is known as plasma. The

atomic components recombine outside the electric arc and release their

energy as heat and light. At this point powdered coating material

suspended in a carrier gas is injected into the plasma and is subsequently

melted and propelled at high velocity to the workpiece. In practice, a

small amount of a secondary gas such as hydrogen or helium is mixed with

the primary gas such as nitrogen or argon to increase operating voltage

and thermal energy. The plasma system is capable of producing exit gas

velocities of more them 10,000 feet per second and propelling powder

particles at velocities above 2,000 feet per second. These conditions

give rise to high density coatings and coating bond strength adhesion to

steel exceeding 10,000 pounds per square inch in the case of tunbten

carbide/cobalt coating material. This coating bond strength is greater

than can be measured with the standard ASTM C-633 test method. The plasma

spray process is a well developed method offering versatility and control

for the deposition of almost any powdered material ranging from metals,

ceramics, and even polymer materials. As with other thermal spray

processes, the choice of gases, power levels, and other variations of the

plasma system have been carefully established by the manufacturer to

produce the highest quality coatings and best economics.

Vacuum Plasma

Plasma spraying is conducted in air for most applications, however,

the need for ultra high performance coatings of high purity has lead to

plasma spraying within a low pressure, inert environment vacuum chamber.

Under low pressure, the configuration of the jet emerging from the plasma

nozzle is drastically different in character from that obtained under

atmospheric pressure. It is much longer and the turbulence at the jet

P29-5
- 6 -

boundary is considerably lower. The extended plasma in an inert environment provides:

1. A longer heating zone, permitting increased dwell time for

efficient particle melting.

2. High plasma temperature well down stream of the nozzle as a

result of reduced turbulence which minimizes cooling and

mixing with the surrounding inert gas.

3. Increased spray pattern width since the nozzle to workpiece

distance is increased.

4. Greater tolerance to changes in spray distance.

The coating advantages by spraying in a low pressure, inert

atmosphere environment can be categorized as follows:

1. High coating adhesion due to improved interface conditions such

as high preheat and operating temperatures without detrimental

surface oxidation.

2. Excellent coating thickness control.

3. Minimum porosity.

4. Improved deposition efficiency of impacting particles.

5. Minimal particle reaction with oxygen during spraying.

The high quality coatings achieved by low pressure plasma spraying

are finding immediate application in the coating of turbine blades for

jet engines. Initial tests by General Electric's Research and Development

Center and Gas Turbine Division has shown that low pressure plasma sprayed

coatings will extend turbine blade service to over 40,000 hours in hostile

corrosive environments. This method at least triples the life of uncoated

blades under such conditions and represents a significant improvement over

a currently used coating technique. In another application, jet engine

P29-6
- 7 -

turbine blade tips damaged from erosive wear are recycled through low

pressure plasma spraying by depositing heavy coatings on the damaged

surfaces followed by machining to original dimensions. Both applications

result in direct conservation of critical materials through the use of

thermal sprayed coatings. Precious turbine blade superalloy components

can be made to last longer at a cost saving unequaled by other techniques.

The major components of a low pressure plasma spray system are a

vacuum tank, vacuum pump, gun and workpiece manipulators , and the normal

components of a plasma system. The low pressure plasma system is not

restricted to jet turbine applications but is expected to find uses in

areas such as piston rings, hard facings for valve seats, and thermal

barrier coatings and all areas where a high performance coating is

required.

Detonation

Another method of thermal spraying is the detonation process. This

process operates by exploding metered amounts of a gas mixture in a gunlike barrel into which powdered material is injected. The spray material

is heated to a molten or semimolten state and is transported down the

barrel by the shock waves and expansion of the exploding gases. The

detonation process produces coatings which function similar to that of

plasma spraying. The process is primarily used for deposition of relatively

thin (0.010 in.) hard surface coatings' of tunsten carbide. However, due to

the necessary process controls and high operating noise level, it is

restricted to laboratory conditions and simple part geometries.

Electric Arc Process

The last commercial thermal spray system is the electric arc wire

process. In this process, two electrically conductive wires are charged

P29-7
- 8 -

with direct current and an arc is created at the wire tips melting the

material. A jet ©f high velocity compressed air atomizes the molten

aaetal and projects it on to the workpiece. The arc wire spray system

is characterized by wide spray profiles, high deposition rates, and

strong coating adhesion to steel substrates. Since the process uses

only electricity and compressed air, it lends itself to easier moving

of equipment from one installation to another and without the need of

stocking oxygen and fuel gas supplies. Table I compares the relative

cost and other factors of the processes discussed.

Automation

The thermal spray coating process is readily adaptable to automation and each system can be operated from a manual mode for occasional

use up to fully automatic operation. Dp to five degrees of gun and work

motion freedom are achieved with numerical control microprocessors.

The state of the art of plasma spraying permits preprogramming of conditions and routines followed by single push-button start-up , finish, and

monitoring of conditions during deposition.

THERMAL SPRAY APPLICATIONS

The thermal spray coating process lends itself to coating items of an

extremely . wide variety of sizes and geometries. Typical part configurations

include piston rings, journals, conveyors, shifter forks, extrusion dies,

transformer cases, ship hulks, ship tanker compartments, and all the way up

to suspension bridges. Each application directly results in critical material

conservation through reduction of wear and corrosion and greatly prolonging

part service life by allowing use of a high performance coating material over

a non-critical base only where required. Overall, applications of the thermal

spray process can be categorized into the following areas:

P29-8
Wear resistance

Oxidation resistance

o Corrosion resistance

. Restoration of dimension

. Abradability and clearance control

. Thermal barriers

. Electrical conductivity or resistivity

These applications are served by choices of over 150 different coating

materials with different characteristics of toughness, coefficient of friction

hardness, and other properties. These materials can be categorized into the

following groups:

. Pure metals

. Metal alloys

. Cermets

. Ceramics and oxides

. Polymers

. Special composite materials

The industries served by thermal sprayed coatings are’ extremely broad

and include: aircraft, railroads, automotive, petroleum, textiles, paper,

food, and power generation.

MATERIAL CONSERVATION WITHIN THERMAL SPRAYED COATINGS

Current research in the field of thermal sprayed coatings is taking the

direction of further conservation through coating metals substitution and

ceramic substitution for metals. A new family of plasma sprayed, ferrous base

powdered composite materials incorporating small amounts of active metals have

been introduced to the marketplace. These materials are able to replace high

chromium containing coatings in many abrasive wear applications.
-iOSignificant research is being conducted in the area of oxide and ceramic

coatings. Ceramic coatings offer several attractive properties compared to

metals

1. Manufacturing costs are lower since extraction is not required,

thus saving energy.

2. Ceramic materials are very resistance to wear, oxidation, and

corrosion relative to metals.

3. Ceramics offer significant weight savings over metals.

4. Ceramics are frequently more available than equivalent high

performance metal alloys.

Thermal sprayed coatings of ceramics have found vast applications with

regard to wear and oxidation resistance. Plasma applied magnesium zirconate

has long been used to protect the superalloy structure of jet engine combustion

chambers against oxidation and current research has shown that a thin, insulating

layer of thermal sprayed ceramic over gas turbine blades can significantly raise

the ceiling of operating gas temperatures and corresponding efficiency.

International Business Machines uses thermal sprayed coatings to protect

more than 48 different computer parts from wear. In the IBM 5424 card sorter,

a chromium oxide coating extended life from 40,000 operations using metal alloys

to over 1.5 million without measurable wear. In another wear application, TRW

Corporation has demonstrated up to three times longer life using ceramic coated

piston rings relative to hard chromium plated rings in engine tests. Under

abrasive wear conditions, ceramics have been shown to outlast high chromium

alloys and tungsten carbide-cobalt containing coatings. Current research on

thermal sprayed ceramic coatings is focused on enhancement of properties such

as toughness, relative ductility, and thermal resistance.

P29-10
- 11 -

FUTURE CONSERVATION WITH THERMAL SPRAYED COATINGS

Die future direction of critical materials conservation on an industrial

and national level should rely on two primary factors. First, the establishment

of a positive incentive toward the national need for conservation of scarce

material resources. Second, an expamding awareness of the potential for

techniques such as thermal spray coatings to meet this national need.

Hide industrial use of thermal sprayed coatings should be encouraged

through the following methods:

1. Shift from critical bulk materials to coatings applied over noncritical metals.

2. Expand the use of coatings in OEM areas.

3. Promote salvage of critical material parts through restoration by

coatings

P29-11
TABLE I

MAJOR

mm.

SPRAY

SYSTEMS

COMPARISON

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P29-12

APPROXIMATE

SYSTEM

COSTS.
REFERENCES

Cl),

(3)

(2) R.A. Lula, Effects of Materials Shortages on Stainless

Steel Technology, Metal Progress, Oct. 1979, pg. 60

D.E. Fink, Availability of Strategic Materials Debated,

Aviation Week and Space Technology, May 5, 1980, pg. 42

P29-13
OPPORTUNITIES FOR CONSERVATION AND SUBSTITUTION

OF CRITICAL METALS UTILIZING RAPID SOLIDIFICATION TECHNOLOGY

AND NEAR NET SHAPE PROCESSING

Arden L. Bement Jr,

TRW Inc,

P30
OPPORTUNITIES FOR CONSERVATION AND SUBSTITUTION

OF CRITICAL METALS UTILIZING RAPID SOLIDIFICATION

TECHNOLOGY AND NEAR NET SHAPE PROCESSING

Arden L. Bement Jr.

Vice President - Technical Resources

TRW Inc.

KEYNOTE TALK

P30-1
OPPORTUNITIES FOR CONSERVATION AND SUBSTITUTION

OF CRITICAL METALS UTILIZING RAPID SOLIDIFICATION

TECHNOLOGY AND NEAR NET SHAPE PROCESSING

By Arden L. Bement, Jr.

INTRODUCTIO N

Good morning ladies and gentlemen'. It gives me great

pleasure to introduce a session which brings before you a group

of distinguished speakers who will describe processing

technologies which hold great promise for not only conserving

energy and the use of critical metals but also facilitating the

design of new alloys with substantially improved properties.

The number of developments in new processing technologies

over the past two decades have been unprecedented in history.

In most cases these developments were spurred by advances in

alloy design and the necessity of removing trace elements,

inclusions, and grain boundaries which limit the temperature

performance capability of superalloys. Subsequent to the

dramatic improvements in the temperature capability of wrought

and cast superalloys made possible by vacuum - indue t i on and

vacuum -arc melting in t he 1950' s, the increased macro- and

micro-segregation brought about by increases in alloy content

in advanced alloy designs soon defined an upper plateau in the

further temperature capability achievable with ingot

metallurgy. Rapid solidification processing has provided new

opportunities to rise above that plateau by promoting increased

solid solubility, compositional homogenity and new modes of

grain boundary modification.

Other revolutionary processing developments in superalloys

have also emerged during this period, to include:

1. The application of directional solidification (or

recrystallization) to produce both single crystal and

columnar grained Y' perc ip i tat i on hardened or

P30-2
eutectic-strengthened Y/Y'-aMo and Y/Y'-TaC turbine

blade alloys

2. The application of superplastic forging and hot

isostatic pressing to turbine disk alloys

3. The use of vacuum investment casting for cobalt-base

vane alloys and directional solidification and oxide

dispersion strengthening (ODS) for nickel-base alloys.

The last decade has also seen the increasing use of stepped

hot-die forging, isothermal forging and superplastic forging

of a+ft and ft titanium alloys for engine fans, compressor blades

and disks, and for aircraft structural components. The high

response of these alloys to superplastic forming and diffusion

bonding has made possible dramatic cost and weight savings

(ranging from 30 to 60 percent) and reductions in buy-to-fly

ratios to two and less in complex structural shapes. The

resulting reductions in machining chips resulting from these

near net shape forming technologies now amounts to hundreds of

thousands of pounds annually.

Advancements not only in the casting of s i ng 1 e -c ry s t al

turbine blades but also in the split-mold investment casting,

centrifugal casting, ferrous die casting, squeeze casting and

isothermal casting of large, complex structures have also been

highly notable achievements over the past two decades.

Furthermore, the hot isostatic pressing of net-shape cast

components to qualify them for applications which would

normally require the tensile, fatigue and toughness properties

of machined forgings has been an especially dramatic

de ve lopment

Although many of the inventions in processing technology

over the past twenty years have been piloted by superalloys and

titanium alloys, because of their high performance requirements

and raw material costs, a greatly increased interest in the

near net shape and rapid solidification processing of a 1 urn in urn

and iron-base alloys has developed during the past decade

P30-3
spurred on by requirements for weight reduction, critical

materials substitution, increased temperature performance

capability, energy savings, and the opportunities in

fabrication and tool design offered by CAD/CAM technology.

Three trends deserve attention as we proceed further into

the 1980's:

1. The economic incentives for conserving energy and

critical materials will become increasingly stronger

stimuli for the development of new processing

inventions and know-how.

2. The developments in processing technology will

increasingly lead developments in alloy design and

will provide opportunities not only

for the substitution of critical materials but also

for their displacement by improved alloy design (e.g.,

the displacement of cobalt-base vane alloys with

directionally-solidified and

ox ide -d i spe r s i on - st reng t hened nickel-base alloys).

However, the increasing fractions of development costs

assigned to the performance qualification and data

base generation for new alloys and the decreasing cost

fraction attributable to the alloy design, per se,

will enforce a higher degree of selectivity on those

alloys allowed to proceed to commercial scale-up.

3. The unavailability of capital resources and the

impeding effects of inflation on both the introduction

of new processing technology and the increase in

production capacity needed to keep up with demand may

have more of an impact on our critical metals

dependence than our current use patterns. As the

nation and industry adopt rational procurement

policies and introduce stockpile countermeasures, the

economic and lead-time criticality of supply

P30-4
disruptions, and hence the threat of their occurrence,

should decline.

The general term "near-net - shape processing" applies to

metal solidification processing, wrought metal deformation

processing and powder metal consolidation processing. However,

the remainder of my comments will focus on rapid solidification

processing, since it is the newest of these technologies to

emerge

THE PROMISE OF RAPID SOLIDIFICATION PROCESSING

Rapid solidification processing opens up a new world of

alloy systems and microstructures which are not possible in the

ingot world. With this technology a broad spectrum of

structural forms ranging from amorphous "glassy metals" to

highly-refined microcrystalline alloy structures can be

produced by a variety of processing techniques. These include

splat cooling, roll quenching, melt extraction, gas

atomization, ultrasonic atomization, centrifugal atomization,

rotating electrode atomization, laser or e lec t ron -beam surface

glazing as well as others. In order to achieve the beneficial

effects of rapid solidification, cooling rates in the range of

10^- 1 0^°C/sec are desirable; however, some benefits are

only obtained near the higher end of this range.

In the case of rapidly solidified powders a number of

relatively conventional techniques can be used for powder

consolidation. These include cold compaction followed by hot

pressing; direct hot mechanical pressing, rolling, or

extrusion; hot isostatic pressing, and others depending upon

the alloy and powder cha rac t e ri st i c s

Interest in rapid solidification has increased dramatically

throughout the world since the pioneering work of Pol Duwez in

1960^^ in splat quenching from the molten state . Although

Duwez and his associates anticipated many of the structure and

property potentials for amorphous and microcrystalline alloys

P30-5
produced by splat cooling, it remained for others to fully

appreciate that the benefits of rapid solidification could be

achieved in bulk sections through appropriate consolidation

technique s

The general benefits of rapidly solidified alloys are as

follows:

1. Substantial extensions in solid solubility can be

achieved, and in some instances the extended

solubility of one component will promote the

solubility of others. This enhanced solubility not

only provides greater sol id - solut i on hardening but

also promotes a higher volume fraction of precipitates

during subsequent aging treatments. It also retains

undesirable impurities in solid solution that would

degrade grain boundary and interface properties,

promotes m i c ro s t ruct u ra 1 stability through the reduced

kinetics induced by high melting temperature solutes,

and allows the additional solute content for forming

more -p ro t ec t i ve surface scales for corrosion and

oxidation resistance.

2. A high degree of homogenity can be achieved, reducing

the free energy of the alloy system and contributing

to both structural and chemical stability.

3. High levels of mic rost ructural refinement can be

achieved to enhance low temperature strength,

ductility, fracture toughness, and fatigue life.

Furthermore, the stabilization of fine grain

structures with highly dispersed precipitates or inert

particles can promote superplastic behavior and reduce

embrittlement responses in transformed structures.

4. Metastable phases, which would not occur at the low

solidification rates of ingot metallurgy, can be

formed, and

P30-6
5. Metallic glasses can be formed which exhibit unusually

high fracture strength, corrosion resistance, and wear

resistance to include excellent magnetic properties

for some metallic glasses.

Since the other presenters in this session will describe

alloy developments and near net shape manufacturing

technologies in some detail a few examples of important new

alloy development s which have the potential of displacing

- critical metals will suffice.

1. Nickel-base Superalloys

f 2

)

Pratt § Whitney investigators have developed one

of the strongest superalloy compositions to be

developed over the last few years containing an

enhanced solid solution strengthening of Y

1 by

molybdenum and tungsten. This alloy, containing 6.8

w/o Al, 14.5 w/o Mo, 6.2 w/o W, and 0.6 w/o C,

exhibits both an excellent response to diffusion

bonding and good compatibility with conventional types

of protective coatings. Therefore, it is one of the

leading candidate alloys for the radial wafer turbine

blade concept under development by Pratt § Whitney

Aircraft. This high-solute alloy can only be used in

powder form, since severe segregation would occur

during conventional ingot casting. Rapid

solidification processing offers two general

opportunities for backing out cobalt from nickel-base

superalloys

1. Development of cobalt-free, enhanced - solute

superalloys which have greatly enhanced creep and

st re ss - rupture properties, and

2. The modification of conventional alloys to trade

off enhanced properties for reduced cobalt

content

P30-7
As pointed out by Tien* superalloys may not

require the present levels of cobalt to deliver

acceptable performance. He further points out that

the substitution of nickel or other elements for

cobalt in superallovs could result in a 10 percent or

more reduction in the total US yearly demand for

cobalt .

2. Aluminum Allovs

' f 4 1 The Air Force Materials Laboratory has had

promising success in developing high temperature

aluminum alloys by rapid solidification processing

which exhibit superior creep strength compared with

2xxx alloys currently in use -for high temperature

service. If these alloys, based upon the Al-Mn-Co,

Al-Fe-Co (alternately Al-Fe-Ni), Al-Fe-Mo, and

Al-Fe-Ce systems, prove promising for service at

temperatures in the range of 450° to 650°F (230°

to 540°C) they could displace titanium and alloy

steels for some aircraft structural applications.

3. Iron-base Alloys

Slaughter and Das^^ have investigated iron-aluminum

alloys containing TiR. as a dispersion strengthening

phase to provide a viable substitute for

chromium-bearing stainless steels currently used in

critical jet engine compressor components.

Preliminary work has shown a 20o weight reduction and

a 11U°C improvement in heat resistance over current

ferritic stainless steels.

These studies are continuing in collaboration with

Ohio State University to explore the mechanical

properties and m i c ro st rue t u ra 1 characteristics of

Fe-Si-Al alloys fabricated from rapidly solidified

powder. The expectation is that these alloys could be

very attractive replacements for stainless steels and

P30-8
super alloys for intermediate temperature

( 600- 1 000°C ) , ox idat i on - re s i stant applications and

that the brittleness normally exhibited by these

alloys when prepared by ingot metallurgy can be

overcome to acceptable levels with rapid

solidification powder metallurgy.

The examples given above are a selected few to illustrate

alloy developments currently underway which offer opportunities

for direct critical metal substitutions. Equally important are

such other developments as the following:

1. The increase in forging capacity and reduction in

forging temperatures through improved superplastic

response. This would have three major benefits:

a. increased applications of precision hot-die and

isothermal forging for precision net-shape

fabrication

b. use of less strategic, lower- temperature alloys

for die materials, and

c. the shift in forging demand from the 10,000 to

50,000 ton press size range to the 1000 to 5000

ton range, which represents the peak in our

national forging capacity

2. Extend the life of high performance ball and roller

bearings by improving their corrosion resistance and

reducing the size of brittle second phases which limit

fatigue life.

3. Explore the formation of amorphous surface layers by

laser or e lec t ron -beam glazing which would greatly

improve the environmental resistance and provide a hard facing for those steels and superalloys which are

subjected to elevated temperature erosion-corrosion

service.

4. Enhance the properties of alloys containing lesser

amounts of critically available alloys in an effort to

P30-9
meet the performance requirements of alloys containing

high contents of strategic elements.

CONSTRAINTS

As in most emerging technologies there are potential

drawbacks and cautions which can limit the extent and pace of

development and application. A few of these are outlined

be low:

1. Since the effective cooling rate of the powder

particles varies inversely with size, powder -maki ng

processes which produce a broad particle size

distribution would require sieving to achieve

homogeneity in the consolidated product. Some

processes, such as centrifugal atomization, produce

highly uniform distributions and require less

classification.

2. Powder handling operations which employ environments

which are not totally inert introduce potential

explosion hazards and can contaminate the particle

surfaces. Although these contaminants can often be

removed by vacuum and electron-beam assisted

degassing, the additional handling imposes a cost

penalty and can have deleterious

effects on the properties of the consolidated

product. As a rule future processing flow sheets

which provide direct consolidation (such as spray

rolling, 1 aye rg la z i n^il^ etc.) after powder formation

in a totally enclosed inert atmosphere will most

likely produce the highest quality products and

provide major economic advantages.

3. Molten metal which comes in contact with ceramic

liners, pouring tuns, and insulating surfaces are

likely to carry over foreign inclusion particles into

the finished part. This is a serious problem for

P30-10
highly stressed HIP'd turbine disks which are

susceptible to low-cycle fatigue. Current practice is

to screen the powders to eliminate those nonmetallic

inclusions which can significantly reduce the number

of cycles to failure in low-cycle fatigue. Screening

at these fine powder sizes (-150 mesh and finer)

entails a number of difficulties and could probably be

avoided by containerless or cold-hearti) (laser-, a rc

or electron-beam) melting coupled with the rigorous

maintenance of inert processing conditions.

4. Careful attention to gas entrapment during powder

processing, especially in superallovs, is required

since such entrained gases can give rise to

thermally-induced porosity which can serve as fatigue

initiation sites at service temperatures.

5. The impedence of boundary migration during directional

recrystallization by second-phase particles, low angle

boundaries, and stacking faults in rapidly-solidified

super alloys is not well understood. Since this

process is relied upon to establish columnar grains

with a preferred crystallographic anisotropy and grain

boundary alignment in blades and vanes, any lack of

process control can seriously affect production

yields.

6. Finally, the theoretical base for describing

nucleation and growth, phase equilibria, heat

transfer, and the structural and compositional

stability of rapidly solidified alloys is only

partially developed and not well proven

experimentally. This is an area that will require

sustained attention and support.

P30-11
CLOSING STATEMENT

Since I have focused primarily on rapid solidification

powder processing in my keynote remarks, I should mention in

closing four important development areas requiring attention

for the increased application of near-net -shape wrought metals

processing. These are as follows:

1. There is a need for advanced nondestructive evaluation

techniques for detecting subcritical size flaws in

non-sonic geometries. The re a re three approaches to

this problem that look promising. The first is the

automatic, adaptive alignment of the ultrasonic

transducer to maintain orthogonality to the surface of

the part. The second is the use of higher frequencies

and sp re ad - sp ec t rum techniques to suppress unwanted

reflections from the free surfaces and grain

boundaries. Because of the h i gh ly- re f i ned

m ic ro s t rue t u re s in rap id ly- so 1 i d i f i ed powder

metallurgy products, background noise from internal

reflecting and scattering sites is intrinsically low.

The third approach is to use a water-coupled, matching

part which constructs the sonic geometry for

inspection.

2. There is a need for continued attention to lubricant

development for hot-die forging and i sot he rmal -f o rg i ng

operations.

3. There is need for improved, interactive, CAD/ CAM

systems for die design and manufacture for a variety

of near-net - shape applications to include hot die

forging, extrusion, radial forging, hot ring rolling,

shear spinning and various forms of shell and sheet

f o rmi ng .

4. There is a need for processing technology to reclaim

critical metal content from electrical chemical

machining sludge, grinding swarf, and other forms of

P30-12
scrap. Even with today's advances in near-net - shape

forming technologies, considerable critical metal

value is present in these forms of scrap, much of

which is exported abroad.

In closing, I am looking forward to the presentations which

follow and in identifying with you the action topics for these

technologies which are deserving of national attention.

1607A

P30-13
REFERENCES

1. P. Duwez, R. W. Willens and W. Klement, J. Applied Physics

Vol. 31, p. 1156, 1960.

2. R. E. Anderson, A. R. Cox, T. D. Tillman and E. C. van

Reuth, Rapid Solidification Processing Principles an d

Technologies IT, Proceedings Second International

Conference on Rapid Solidification Processing, Reston, VA.

Claitor's Publishing Div., Baton Rouge, LA, pp. 416-429,

1 980.

3. J. K. Tien, T. E. Hawson, G. S. Chen and X. S. Xie, J.

Metals, Vol. 32, p. 12, 1980.

4. C. M. Adam and R. G. Bourdeau, Ra pid Sol idificati on

Processing Principl es and Technologies II , Proceedings

Second International Conference on Rapid Solidification

Processing, Reston, VA, Claitor's Publishing Div., Baton

Rouge, LA, pp . 246-259, 1980.

5. E. R. Slaughter and S. K. Das, Rapid Solidification

Processing Principles and Technologies II , Proceedings

Second International Conference on Rapid Solidification

Processing, Reston, VA, Claitor's Publishing Div., Baton

Rouge, LA, pp. 354-363, 1980.

1 6 0 7 A
R LEER P.NCr.S

1. P. Duwez, R. W. Willens and W. Element, J. Applied Physics

Vo 1 . 31, p. 1136, 1960.

2. R. E. Anderson, A. R. Cox, T. D. Tillman and E. C. van

Reuth, Rapid Solidification Processing Principles an d

Techn o lop ics T T

, Proceedings Second International

Conference on Rapid Solidification Processing, Reston, VA.

Claitor's Publishing Div., Eaton Rouge, LA, pp . 416-429,

1 980.

3. J. K. Tien, T. E. Hawson, G. S. Chen and X. S. Xie, J.

Metals, Vol. 32, p. 12, 1980.

4. C. M. Adam and R. G. Bourdeau, Rapid Solidification

Processing Principles and Technologies II , Proceedings

Second International Conference on Rapid Solidification

Processing, Reston, VA, Claitor's Publishing Div., Baton

Rouge, LA, pp. 246-259, 1980.

5. E. R. Slaughter and S. K. Das, Rapid Solidificati on

Processing Principles and Technologies II , Proceedings

Second International Conference on Rapid Solidification

Processing, Reston, VA, Claitor's Publishing Div., Baton

Rouge, LA, pp . 354-363, 1980.

1 6 07 A
POTENTIAL OF RAPID SOLIDIFICATION FOR REDUCTION OF CRITICAL

ELEMENT CONTENT OF JET ENGINE COMPONENTS

Joseph Moore and Colin Adam

Pratt & Whitney Aircraft

P31
POTENTIAL OF RAPID SOLIDIFICATION FOR REDUCTION

OF CRITICAL ELEMENT CONTENT OF JET ENGINE COMPONENTS

Joseph Moore and Colin Adam

Pratt & Whitney Aircraft

Government Product Division

P31-1
Good Morning.

My presentation to you today will be to discuss rapid solidification processing as it relates to the reduction of strategically critical elements in the jet engine. The specific

technique that I will be speaking to you about is the RSR Powder

Metallurgy Process, which is shown in the first chart. The

process is one whereby a liquid stream of metal is poured onto

a rapidly spinning disk, centrifuged into fine particles, and

quenched in a high conductivity helium gas environment. The

process causes the ejected metal particles to solidfy at

rates of cooling in excess of 100,000 degrees per second, with

resulting near perfect chemical homogeneity, closely duplicating

the homogeneity of the liquid from which it came. The work that

I will be addressing deals with nickel, steel, and aluminum alloys,

all of which have application to our jet engine product line.

To provide some perspective as to the characteristics of

solidification in the RSR process, I refer to the second figure.

In this chart is shown the cooling rate capability of particles

varying in diameter form approximately 0.1 micron to 1000 microns.

P31-2
- 2 -

Shown on the chart is the condition for film heat transfer

transfer coefficient equal to infinity, and the condition for

the RSR process, for droplets being accelerated from a central

source such as a rotary atomizer into the quench media. As

can be seen, for the condition h = °°, solidification rates

5 from 10 degrees per second and up occur for particles 1000

microns or finer. In the RSR process, the same consideration

can be made for particles 100 microns or finer. Our past

experience with powder metallurgy alloy, as it was first applied

to our F100 engine program (and specifically to superalloy

turbine disks), showed that it was feasible to work within the

regime of 10 to 100 micron powder particles for consolidification

to high quality product, without imposition owing to very fine

powder features or to the contamination such as oxygen getering

normally associated with talc type materials. Many people have

conducted studies in the field of rapid solidification and it

. 5 is accepted that cooling rates of 10 and higher can be considered

as the splat range, in which chemical segregation of highly

alloyed materials is minimized to the point whereby, on subsequent processing under controlled conditions, it can be essentially

P31-3
-3-

eliminated. The actual device that is being used by the Pratt

& Whitney organization is shown in the following chart. It is

presently capable of handling up to 300 lbs of metal in a

batch mode. The furnance operation is vacuum induction and,

initially, the charge of metal is heated under vacuum until

a liquid, at which time the device is backfilled with helium

gas the turbine activated, and pouring commenced from the melting

crucible onto the disk. We initially started the project

whereby the helium gas was injected and allowed to dump to

atmosphere. The present form of operation is to recirculate

the helium in a closed-loop manner thereby providing an all over

practicality and a degree of economic utility that heretofore

was not achieved. The powder, subsequent to centrifuging and

solidification, is collected by means of cyclone separators.

Overally, the machine operation relies on three basic elements:

1) state-of-the-art melting which can be converted from vacuum

to inert gas melting, 2) high speed turbomachinery for the

centrifical atomization and 3) heat transfer based on the local

heat profile of the solidifying particles as they are ejected from

the atomizer. We have worked with the device since 1976 and the

P31-4
-4-

work that I will refer to from this time on is work that has been

sponsored by ARPA, the Advanced Research Projects Agency, in

Washington, and the AFWAL Materials Laboratory at WrightPatterson Air Force Base, Ohio.

The first slide that I would like to show you is that of

creep deformation of an RSR developed alloy which contains no

critically short elements. It has no chrominum, no tantalum,

nor any cobalt, of which to us are elements that need to be

addressed from a standpoint of minimizing their use. We

found by processing in the RSR mode and allowing the materials

to undergo a gradient anneal leading to directional recrystalliza^

tion that the metal was significantly strengthened in a creep

deformation mode far above that possible by our present alloys,

in this case designed MAR-M200. The test which is shown was one

conducted at 1800°F and 30,000 psi, which is a critical design

point for turbine airfoils in military jet engines. What is

shown specifically is that the RSR materials with no critical

elements, can withstand substantially more time at temperature

and load than can our best material of today. It should be

noted that our current material contains approximately 12 percent

P31-5
-5-

cobalt and about 9 percent chromium.

On the following slide is shown a more recent development

with the same base alloy relative to its endurance capability

under conditions of high temperature oxidation. In this case,

the base alloy in the previous chart was alloyed with minor additions

of hafnium and yttrium in the less than 1 percent range and had

a minor of chromium addition of 3 percent. What can be seen

is that, whereas the initial base alloy as suggested by endurance

in cyclic oxidation was not significantly better than our

current alloy, the modification with the minor element additions

has increased its resistance to oxidation many times. in fact,

in the test shown here at 2100°F, when measuring a weight loss

per unit area factor, there is no discernible evidence that the

modified base alloy was degrading in the environment for at

least the period of time shown in the chart. This test is

on going and the results of more prolonged exposure are continuing to show that minor element additions to the base alloy

maintain a high degree of oxidation resistance for this otherwise very strong material.

Our interest in this metal is as an air cooled turbine

P31-6
- 6 -

airfoil. As shown on the following chart, and in interpreting

blade metal temperature capability relative to a parameter of

one percent creep in 100 hours which would be considered a

design point for air cooled turbine airfoils, one can see

that this type of material offers approximately 150°F advantage

in temperature capability over our current metals in the stress

range critical for blade design (which is noted as blade

midspan) . This temperature capability increase can be considered

in many fashions to the engine designer. It can lead to better

performance of the machine itself by allowing the turbine inlet

temperature to rise. It can lead to more durability by being

able to withstand higher temperatures while not necessarily seeing

them in an existing environment. Or, it can lead to less costly

fabrication of components by simplifying designs which are

presently used for these parts. Our program with ARPA is

viewing performance as the principal attribute from this

temperature advantage capability. We are presently evaluating

an air cooled, airfoil configuration which we designate a radial

wafer blade. In this configuration, individual wafers which

can be fabricated by consolidating powder and rolling it to sheet

P31-7
-7-

are sectioned and etched with intricate cooling passages.

Subsequently, they are joined together, in our case t by

diffusion bonding, and the final assembly electrochemically

machined to its aerodynamic envelope. Parts to this configuration

have been fabricated from the RSR material and have been

engine tested in the F100 for short periods of time. The results

were positive and suggested that the coupled technology of a

radial wafer blade cooling configuration with new materials

of this type can offer substantial performance improvements

in component capability over todays present materials and

methods of fabrication. To date, some 22 components have been

fabricated by this scheme and, while still a small number, it

suggested that reasonable quality control could be installed

during the individual processing steps and lead to a relatively

high yield of finished parts in the wafer configuration.

The following chart shows two blades which were engine

tested. The parts were instrumented and run in a core engine

and, after eight hours of exposure, which included excursions

through all of the individual mission cycles of a military

tactical fighter engine, the parts showed no degradation

P31-8
- 8 -

nor did the instrumentation suggest that any difficulties were

being experienced during the conduct of test as a result of the

material, the configuration or the manufacturing sequence used.

As we view the performance gains possible I refer to the following

chart. Current technology allows a turbine inlet temperature

of approximately 2600°F for the mission cycles we consider in our

product line. Using the radial wafer blade, in conjunction

with these RSR materials, allows the temperature inlet capability

to rise appreciably. For performance, this rise is of paramount

importance. Also, importantly, it can also be used as a

capability to improve performance to some intermediate step

while taking out the balance of benefit in a durability

improvement to the individual component itself. In program

work to date, this has been confirmed on several occasions

and by numerous laboratory tests.

We have taken the technology beyond that of the superalloys

and are presently looking at the use of rapidly solidified aluminum

alloys to reduce the amount of titanium that we presently

consume in our engine while at the same time, getting additional

benefits of costs associated with ease of fabrication, ie.,

P31-9
-9-

aluminum vs titanium fabrication and of reduced weight simply by

the fact that aluminum weighs less than its titanium counterpart. Our work was directed towards studying iron and molybdenum

additions to an aluminum matrix and what we found was the

ability to produce micro dispersions of an Al^Fe type compound

which allowed these metals to operate at a higher temperature

capability than conventional aluminum alloys

The following chart depicts this capability. A conventional

alloy today has a useful temperature range (from an engine point

of view) up to approximately 350 F. The fan operating temperature

of our present machines begins at near 350 UF and extends to

approximately 650°F. In viewing simply the yield strength and

ultimate strength of the RSR processed aluminum materials, one

can see that the useful yield and tensile strength of the

rapidly solidified alloy approaches 650 F when compared to the

conventional alloy limit of 350°F. We are studying the characteristics

of fatigue of these metals and, in present studies being conducted

by our Florida operations, we are showing that the fatigue debit

is significantly less than that experienced by conventional

aluminum alloys and, in fact, is meeting the goals

P31-10
- 10 -

that would be required for the use of aluminum in at least stator

assemblies such as vanes and cases of advanced military jet

engines. The use of these materials would be a direct substitution

for titanium in these parts.

In the iron area, we have undertaken investigations

dealing with the intermetallic compound Fe^Al . As I am sure

many of you know, the FeAl and Fe^Al compounds were studied

extensively in the late 1950's and the early 1960's because

of outstanding features of oxidation resistance, strength and

light weight of the metals. In the following slide is shown the

actual oxidation degradation of Fe-Al under cyclic conditions

at 2000°F. This particular material was processed by the RSR

process and contained a small fraction of titanium diboride

dispersed during the rapid solidification and for which purpose

I will refer to subsequently. As one can see, the oxidation

resistance is outstanding and, in this case, it is compared

with a current alloy which we use for combustor operations,

HAYNES 188, and also to a chromium containing stainless steel,

Type 347. HAYNES 188 is a cobalt base material, Type 347

stainless has approximately 18 percent chromium. The Fe/Al compound

P31-11
- 11 -

has neither. As I am sure that many of you know, also, the

use of the Fe/Al intermetallic compounds has been negated by

the fact that the metals are inherently brittle. They are

difficult to fabricate and, to a designer, difficult to design

with because of extremely poor ductility. The titanium diboride

which was dispersed as a fine phase during rapid solidification

was found to pin the grain boundaries whereby the materials could

be processed under conditions of very fine grain size control;

the outcome being a noticable improvement in ductility and an

improvement in tensile strength. A nominal 2 percent addition

of titanium diboride, added elementally to the melt and allowed

to undergo rapid solidification t was found to be approximately

optimum for improving the elongation of the material. Our

interest in these types of materials is in the combustor of the

jet engine. On the following slide is shown the creep rupture

characteristic of the Fe^Al compound and, in this case, it is

compared to 310 stainless austenitic steel and 430 stainless

ferritic steel. It is evident that the basic composition

is at least as strong in stress rupture as the 300 series and

while this is considerably less than the presently used

P31-12
- 12 -

compositions such as a HAYNES 188, there is ample opportunity

to make significant improvements in the overall strength

of the system by further alloying additions, now that the

inherently brittle characteristic of the metal has been

eliminated

Overall, relative to strategic metals, we can view the

following slide as an index of risk for various elements that

are used in reasonably large quantities in the engine. Those

which are most notably high risk are cobalt and tantalum. We

use both elements in the hot section of the engine for turbine

airfoils, and cobalt for disks. The superalloys we are studying

have neither cobalt and minimum, if any, tantalum. Chromium,

though presently a low or moderate risk, depending on the political

nature, is being addressed by both the superalloys and the steels

of the Fe-Al type. In the case of the steels, no chromium is

included. In the case of the superalloys, we are looking again at

only minor additions of this element. Titanium, though low

politically in risk, is a high risk relative to supply/demand.

The aluminum alloys that we are looking at are intended to be

a direct substitution for presently used titanium.

P31-13
-13-

Finally, I would like to present a example which shows

the amount of cobalt presently being used per F100 engine.

There is about 900 lbs of cobalt consumed in each build of

the F100. In applying current projections with RSR alloys

the total amount of cobalt can be reduced approximately 50

percent. With long term projections of rapid solidification

alloys, it is reasonable to believe that the overall content

of cobalt per F100 engine can be reduced approximately 75 to 85

percent. In closing, then, I would like to say that rapid

solidification is a process technique which has opened new

doors for improved materials and is allowing the use of elements

not in critically short supply to work on our behalf in substituting for these same strategically limited metals.

Thank you.

P31-14
APPLICATIONS

OF

RSR

TECHNOLOGY

P31-15

AV

214179 812103

btl

117
RSR

S O CO ^ T- If) N- ** O) ^ O • CM CD 5^

Is- £

>

°° <

P31-16

near-perfect

chemical

homogeneity.
COOLING

RATES

POSSIBLE

IN

METAL

POWDER

< 8 JO

<o ®

© o>

(£> it

r- 00

I h

UJm

>

<

3.

P31-17

Particle

Diameter,
CREEP

DEFORMATION

OF

SUPERALLOYS

AT

1800°F

AND

30,000

psi

c

oMi

15

o

0)

o

P31-18

200

400

600

800

1000

1200

1400
OXIDATION

RESISTANCE

OF

SUPERALLOYS

CYCLIC

TESTING

AT

2100°F

P31-19

AV

214668 810605

BET-942
CREEP

RESISTANCE

OF

SUPERALLOYS

>

<

P31-20

1300

1400

1500

1600

1700

1800

1900

2000

Metal

Temp

-

°F
RADIAL

WAFER

BLADE

SCHEMATIC

P31-21

AV

192303 810402

BET-897
MANUFACTURING

SEQUENCE

FOR

RSR

RADIAL

WAFER

BLADE

N.

CT>

P31-22
WAFER

BLADES

AFTER

8

HR

OF

F100

ENGINE

TESTING

P31-23

AV

219640 810605

BET-939
BETTER

COOLING

AND

STRONGER

METAL

(O o ® O ©

® m ' r*- © w

mr- °eo S" >

<

P31-24

Current

RSR

Technology
o in co

co o co

<0(0 0) 0) 0 ' r- T“ H

<M CO UJ > “

<

P31-25

Titanium

Diboride,

Weight

%
CREEP-RUPTURE

OF

STEELS

1001=

Q S to

</> SP 3 jz

£ Q- 0

w ir

°

P31-26

AV

158504 810605

BET-940
2000°

F

CYCLIC

OXIDATION

RESISTANCE

P31-27

AV

219638 810605

BET-932
RISK

INDEX

STRATEGIC

MATERIALS

T>C

TOEaa3

</) % 5 o o os00<0

T—><

in to § ®> ° H

00 LU

00

75 0) TO o 5 £ to TO

IBB o O) a> to

BBB o0. B BBH X

T3o

IE oo E3C3 E3umm n o o O O Eo

TOOMB

P31-28

Tantalum

High

High

Titanium

Low

High
CRITICAL

MATERIALS

UTILIZATION

<0c0) oaU cr g ® w g .E cc

CB 2> £ q uj g c © 5 g c5> 3 Li. C O U

in

22 a>

to tr c — -g aL 'o> o = c O £ lu

P31-29

AV

155625 A

810605

BET-944
ALUMINUM

ALLOY

APPLICATIONS

<Dc

03

>

c

03

LL

P31-30

AV

214184 812303

btl

113
STRENGTH

OF

ALUMINUM

ALLOYS

D 5)

to in to

co o co r (O (J) © ' r- r- r*

CM 00 UJ > “ <

P31-31

Temperature

-

°F

Temperature

-

°F
POTENTIAL OF RAPID SOLIDIFICATION FOR

WROUGHT P/M ALUMINUM ALLOYS

Walter S. Cebulak

Aluminum Company of America

P32
By combining the advantages of aluminum powder

metallurgy, (rapidly solidified particles from molten alloyed

aluminum), with special processing techniques, Alcoa is developing a new family of aluminum alloys.

The wrought P/M aluminum alloying process allows a wide

range of new compositions to be considered, employing

new alloying ingredients and higher percentages of

common ingredients normally not permissible with the

ingot metallurgy process.

New high-strength alloys produced by the wrought P/M

process exhibit fine grained homogeneous structures with

excellent fracture toughness and a high resistance to

exfoliation and stress corrosion cracking.

Alcoa is producing two wrought P/M aluminum alloys

classified in the 7XXX series, initially in billets up to 350

pounds for fabrication into extrusions and forgings.

Designated X7090 and X7091, these alloys have many

distinct advantages over similar ingot metallurgy 7XXX

series alloys designed for high performance application in aerospace and ordnance structures. They represent the

initial step in a program of new process alloy development

which promises further improvements in properties and

characteristics of aluminum alloys.

P32-1
Production Sequence Wrought P/M

Aluminum Alloy Forgings and

Extrusions

To produce wrought P/M alloys, molten prealloyed

aluminum is rapidly solidified using atomization

technology. This rapid solidification refines the dendritic

structure and reduces the size of constituent particles.

The prealloyed powder particles are isostatically

compacted into a green compact which is encapsulated in an aluminum canister.

The canister and compact are vacuum preheated, then

pressed into a billet with 100 percent density.

The canister material is then machined from the P/M billet

surface.

Wrought P/M aluminum billets are subsequently fabricated

using conventional techniques such as forging, extruding or

rolling into sheet and plate.

The solution heat treat and age practices are comparable

to those used for ingot metallurgy alloys.

P32-2
Wrought P/M Aluminum Alloys

X7090 and X7091

Two wrought P/M alloys are now in commercial production. They were

formerly known as MA67 and MA87...then CT90 and CT91, and were recently

designated X7090 and X7091 by The Aluminum Association.

X7090 and X7091 are being produced in billets of 110 pounds and a larger,

350 pound size will be available in the near future.

Wrought P/M alloys X7090 and X7091 offer a balanced combination of high

strength, fracture toughness, fatigue performance and resistance to stress

corrosion cracking and exfoliation.

Nominal Composition

These wrought P/M alloys belong to the 7XXX series of aluminum alloys

since zinc is the major constituent. They also contain magnesium, copper

and cobalt. (See Table 1).

Density and Modulus of Elasticity

Although the density and modulus of elasticity of X7090 and X7091 are almost the same as other 7XXX series alloys produced by ingot metallurgy,

(See Table II), their grain structure is much finer and more homogeneous.

Other physical properties are similar to 7XXX series alloys produced by

ingot metallurgy. (See Table III). Temper Designations

Extrusions and forgings made from alloys X7090 and X7091 are available for

evaluation in various tempers. For forgings these tempers include hot water

quenched, compression stress relieved and non stress relieved.

(See Table IV).

Properties of Extrusions

The typical longitudinal tensile properties of extruded alloys X7090 and

X7091 are shown in Table V. The yield strength of extruded X7090-T7E71 is about 15 percent higher than alloy 7050-T7651X, and X7091-T7E69 shows a 7

percent improvement over 7050-T7651X.

Table V

Typical Tensile Properties For Wrought

P/M Alloy Extruded Shapes

X7090-

T7E71

X7091-

T7E69

X7091-

T7E70

Tensile Strength, ksi (MPa) L 91 (627) 86 (593) 79 (545)

LT 86 (593) 80 (552) 75 (517)

Yield Strength, ksi (MPa) L 85 (586) 79 (545) 72 (496)

LT 78 (538) 74 (510) 67 (462)

Elongation, %-4D L 10 12 14

LT 6 8 10

Note: 0.25 in. (6.4mm) to 1.5 in. (38.1mm) thickness

P32-3
Chemical

Composition

Limits

For

Several

0) JQ

03

P32-4

Note:

Value

maximum

if

range

not

shown.
Density

and

Modulus

Wrought

P/M

and

I/M

Alloys oV o

Vi *,

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P32-5

Table

II
Typical Physical Properties

Approximate Solidus Temperature

X7090 1018°F (548° C)

X7091 1010°F (543° C)

Specific Heat*

X7090 0.203 Cal/g° C

X7091 0.206 Cal/g° C

Thermal Conductivity*

X7090-T7E71 0.33 Cal/Sec 0 C/cm

X7091-T7E69 0.36 Cal/Sec 0 C/cm

Coefficient of Expansion*

68° F - 212° F (20° C - 100° C)

X7090 - 13.2 x 10-6 in/in/°F (23.8 x 10-6 m/m/°C)

X7091 - 13.1 x 10-6 in/in/° F (23.7 x 10-6 m/m/°C)

* Calculated Values

Table III

P32-6
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P32-7

Table

IV
Properties of Die Forgings

The longitudinal yield strength of an X7090-T7E71 forging is about 18 percent higher than a 7175-T736 forging, while X7091-T7E69 is approximately 8

percent higher than 7175-T736.

Table VI

Typical Tensile Properties For

P/M Alloy Die Forgings

X7090-

T7E71

X7091-

T7E69

Tensile Strength, ksi (MPa) L 89 (614) 84 (579)

T 84 (579) 79 (545)

Yield Strength, ksi (MPa) L 84 (579) 77 (531)

T 79 (545) 72 (496)

Elongation, % - 4D L 10 13

T 4 9

Note: < 3.000 In. (76.2mm) Thickness

Resistance to Stress-Corrosion Cracking

Figure 1 shows the percent of short transverse specimens which were

stressed at 35 ksi, surviving after 1600 days exposure in an industrial

atmosphere. Alloys 7050, X7090 and X7091 were given varying amounts of

aging in order to determine their yield strength versus stress-corrosion

resistance. Alloys 7075-T73 and 7175-T736 were given the standard heat

treatments associated with those tempers and represent the normal

strength range obtained using production practices. For a given level of

stress-corrosion cracking resistance, as judged by the percent of specimens

surviving, the P/M alloys X7090 and X7091 can be aged to yield strengths 10

ksi (69 MPa) to 15 ksi (103 MPa) higher than the best high strength I/M

alloys available. The performance shown in Figure 1 was for specimens

taken across the parting plane of a die forging known to have a high degree

of short transverse grain orientation at the parting plane, thus providing a

highly critical test.

100

O)

c

“5 50

d

CO

..p

0

(345) (414) (483) (552)

Short Transverse Yield Strength, ksi (MPa)

Figure 1 SCC-Strength Capabilities

Thin Web-Flange Die Forgings

P/M Alloy X7090 and X7091

Vs. I/M Alloys 7050, 7175, 7075

P32-8
Exfoliation Corrosion Resistance

At highest strengths, test evaluations indicate X7090 and X7091 are as resistant to exfoliation as the 7XXX ingot metallurgy alloys in the highest

strength tempers developed specifically to resist exfoliation, T76.

The graph illustrates the relationship of strength and exfoliation resistance

of I/M and P/M series alloy extrusions in the 48-hour EXCO test. In order to

place the ingot metallurgy 7XXX alloys in the “pitting” classification, the

alloys require aging to the T7 type temper.

Figure 2

Strength - Exfoliation

I/M Vs. P/M 7XXX Extrusions

48 Hour EXCO

65 70 75 80 85 90 95 100

(448) (483) (517) (552) (586) (621) (655) (689)

Longitudinal Yield Strength, ksi (MPa)

Atmospheric Corrosion

Atmospheric exposure tests at the Alcoa Technical Center near Pittsburgh

and Point Judith, Rl indicate corrosion of X7090 and X7091 is uniform and

non-directional.

P32-9
Fracture Toughness

Initial testing of the strength-toughness relationships of the new P/M alloys

indicate their superiority to many of the 7XXX series I/M alloys. Data points

approaching the upper right corner of the graph are preferred.

Alloy X7091 in temper T7E70 (not shown on graph) has high toughness, but

valid data have not been accumulated in the L-T orientation. In the T-L

orientation, measurements of 43 ksi /fir have been recorded in material

with 67 ksi longitudinal yield strength.

Figure 3

Typical Fracture Toughness Vs. Yield Strength

High Strength Aluminum Alloy Extruded Shapes,

0.25 in. (6.4mm) to 1.50 in. (38.1mm) Thickness

co

o'

*

50

40

30

20

10

0

1 1

1 1 1

7175-T7351 1# • 7050-T76511

7075-T73511#

„X7091-T7E69

X7090-T7E71

7075-T651 1 (•)

7178-T7651 1# •

-

7178-T651

1

L-T Orientation

i

i J

i -1i—.—1i 11

50 60 70 80 90

(345) (414) (483) (552) (621)

55

44

33

22

11

Longitudinal Yield Strength, ksi (MPa)

IE

s

CO CL

_o

*

P32-10
Fatigue Strength

Notched axial fatigue strengths of X7090 and X7091 extrusions are 35 to 40

percent better than alloy 7050 and 7075 at 106 and greater cycles. A similar

advantage is indicated over alloy 2024.

Figure 4

Notched Axial Fatigue Strength Of

P/M Alloys X7090 and X7091 Extrusions VS.

I/M Alloys 7050 and 7075 Products

Cycles

Figure 5

Notched Axial Fatigue Strength Of

P/M Alloys X7090 and X7091 Extrusions Vs.

I/M Alloy 2024-T351 Rod and Bar

Cycles

P32-11

Maximum

Stress,

MPa

Maximum

Stress,

MPa
Wrought P/M Alloy and Process Development

Since the early 1960’s, scientists and engineers at Alcoa’s Technical Center

have been developing wrought P/M alloys and the technology needed to

produce them in commercial quantities. This developmental work has

included evaluations of more than 400 experimental compositions and

temper variations.

Alcoa has invested considerable financial and human resources into a number of research projects. Many of these projects were supported by

Federal agencies. Such support, instrumental to our progress in the past, is continuing.

Each government funded project has led either to the development of a new

alloy with an optimum combination of properties or to improved understanding of the production process.

Nearly half of the projects involved the participation of major aerospace

companies. AFWAL is considering the sponsorship of multi-million dollar

projects to develop alloys with new combinations of strength, elastic

modulus and structural integrity at elevated temperatures.

Government Funded P/M Programs

Alcoa R&D Laboratories

Subject Contract Number

Government

Agency

Other

Participants

Precision Aluminum Alloy Powder Metallurgy

Structural Components

Elevated Temperature P/M Alloys

F3361 5-77-C-51 29

F3361 5-77-C-5086

AFWAL

AFWAL

GD/Ft. Worth

Lockheed-Burbank

Boeing Vertol

Fundamentals of Compaction Processes for Rapidly Quenched, Prealloyed Metal Powders F3361 5-79-C-5037 AFWAL —

Optimization of Fatigue Resistant P/M Alloys F3361 5-77-C-51 74 AFWAL —

Advanced Aluminum Alloys from Rapidly

Solidified Powders for Aerospace

Structural Applications F3361 5-77-C-5203 AFWAL DARPA

LockheedPalo Alto Labs

Advanced Aluminum P/M Alloys for SCAR

(Supersonic Cruise Aircraft Research)

NASI-14625 NASA Lockheed-Burbank

Production and Rolling of Al-Lithium P/M Alloys DAAK 10-78-C-0410 ARRADCOM —

Thermomechanical Processing of ARRADCOM Billets DAAK 1 0-78-C-0255 ARRADCOM —

P/M Mill Product Process Optimization DAAK 10-79-C-0193 ARRADCOM —

Direct Vacuum Extrusion of High

Strength P/M Alloys

F3361 5-79-C-5053 AFWAL Boeing

McDonnell-Douglas

Cobalt free high strength

aluminum P/M alloy

F33615-80-C-5098 AFWAL Boeing

Alloys With Increased Elastic Modulus Proposal AFWAL

Structural Elevated Temperature Alloys Proposal AFWAL

P32-12
Goals of Alcoa’s Wrought P/M Alloy Program

1. To develop and evaluate improved alloys with the variety and

combination of properties which are realistically attainable.

2. To evaluate present production operations at Alcoa’s facility and

to expand production capacity in both billet size and total tonnage.

3. To obtain joint participation between Alcoa, commercial aerospace

companies and government agencies. This participation is to include

testing, evaluation and service trials of available products. This

will enable feedback on cost effectiveness which is essential in defining the required future production capacity.

Benefits for Hardware Builders and Users

The benefits to designers and manufacturers of aerospace and ordnance

equipment are:

1. Greater understanding of the new materials’ behavior in service.

2. Improved ability to evaluate P/M alloys for cost effectiveness

relative to improved properties and performance.

3. Knowledge required for efficient use of wrought P/M alloys in design and manufacture of finished products. Experience to date

indicates when using wrought P/M alloys there is no need to change

the fabrication processes from those used with ingot metallurgy alloys.
Benefits to the Material Producer

Through joint participation in the evaluation of these new wrought P/M

alloys, Alcoa expects to increase its understanding of the production

processes and how they affect properties and costs of finished parts.

Such understanding will be part of the evaluation of the feasibility of

expanding production facilities and will provide assurances that the new

plant will be most efficient and productive -- able to produce wrought

P/M alloys at the lowest possible cost and highest possible quality. For

example, evaluation of direct extrusion of products from green compacts,

eliminating the canister, is underway.

In addition, an improved understanding of present wrought P/M alloys’

performance will enable Alcoa to more accurately predict in-service

behavior of future P/M alloys during their development.

Future Wrought P/M Alloy Developments

Development of other wrought P/M alloys is well along. Experimental alloys

have been produced with special properties. Alloys with yield strengths up

to 124 ksi, with high modulus-density ratios or with increased high

temperature strength are in initial stages of evaluation.

Billets of a 3,000 pound size have been produced and Alcoa has an active

program for development of even larger billets for rolling sheet and plate.

P32-14
Availability

Alcoa can produce alloy X7090 and alloy X7091 extruded bar, rod and shapes

from the present 110 pound billets and from 350 pound billets scheduled to

be available in the near future. Die forgings and hand forgings can also be

produced from the same size billets. Some shapes can be made from

available dies; such as extruded bar 1.5 inches (38.1mm) x 4.5 inches

(114.3mm) cross-section, an extruded seat track section, a ribbed die

forging (Figure 6), or hand forgings.

Rolled plate and sheet are not currently available.

Figure 6

P32-15
POTENTIAL FOR NEAR NET SHAPES

J. Stanley Mosier and Peter G. Bailey

General Electric Comoanv

P33
POTENTIAL FOR NEAR NET SHAPES

J.S. MOSIER and PETER G. BAILEY

AIRCRAFT ENGINE GROUP

GENERAL ELECTRIC COMPANY

CINCINNATI, OHIO

In recent years the demand for improved cost-effectiveness in shape making

and fabrication processes and better utilization of input materials has brought

about developments and advancements in near-^.net-shape technology. As a result, more refined shapes, reduction of costly input material and substantial product

machining savings are achievable. In most cases that we have studied, reduction

of input raw material is ''-50%. Near-net-shape technology becomes increasingly

important for the aerospace industry with rising fuel costs and increased concern over energy and material supply.

About 80% of the materials used in today's aircraft gas turbines are critical

metals such as titanium and nickel-base superalloys. In order to improve the

fuel efficiency of these engine systems, the aerospace industry has continuously

developed new compositions for these alloy systems that are stronger, lighter,

and with higher temperature capabilities. However, the new alloys are often more expensive, more difficult to fabricate and produce products with very high

buy-to-fly weight ratios. Typically, a conventional forging can weigh 10 times

as much as the finished part made from it. Near-net-shape technology thus

becomes a viable alternative to conventional methods for the manufacture of

costly, difficult to fabricate materials.

The materials resource crunch has had wide public exposure recently. One

example is the February, 1981 Reader's Digest article "Strategic Materials: The

Invisible War". Of the 36 non-fuel minerals essential to the United States as an industrial society, we are crucially dependent on foreign sources for 22 of

them. In 1980, we imported 91% of our chromium, 93% of our cobalt, and 97% of our tantalum and manganese. By contrast, we were only 42% dependent on imported

oil. Conservation of materials through near-net-shapes technology will become

increasingly important as a national priority.

The need for total productivity improvement, including material conservation,

is as popular today as the theme from "Star Wars", and has been identified

as a major corporate thrust for most U.S. manufacturers. Projected escalation

estimates indicate that by 1984 labor will be up 250% from 1973 levels and the

cost of some of the high usage materials such as copper, aluminum and steel will

increase 200-300% during the same period. The results of such escalation will be even more acute in the area of specialty aerospace materials. For example,

prices of certain nickel-base superalloys increased 60% in the period from 1978 to

1979. Near-net-shape processes offer the opportunity for significantly improving

productivity by reducing labor, material, and inventory costs as well as curbing

material usage.

P33-1
- 2 -

General Electric's Aircraft Engine'Group has, throughout its' 30-year history,

employed near-net-shape technology. Precision casting is probably the oldest of

these technologies. In the 1960 ' s , J79 turbine shafts were produced by shear

spinning. Precision rang rolling and pioneering efforts of inertia welding

engine rotor spools began in the early 1970's. All of these developments reduced

the input weight of materials. Inertia welded spool construction also reduced

the weight of the finished engine parts by eliminating flanges and bolts.

Except for precision casting, the previously mentioned applications are not

normally thought of today as near-net-shape processes. Currently, we are looking

at all possibilities to reduce input material.

Precision casting - inherently a near-net, or in some cases a net shape

process, is dated by Chinese artifacts to at least 3000 B.C. Today it still has

exciting potential. Capability for larger and more complex titanium and

superalloy shapes are being developed, not only to replace heavier conventional

forgings, but in some cases to eliminate the need for fabrication. Savings

from some applications are in excess of $7,000 per part. The cost of the part made

by casting is not always reduced drastically, but the savings in machining and

fabrication can be very large. Investment in new machine tools to increase

capacity can be reduced. Combined with hot isostatic pressing, the cast properties

can also be enhanced. In some smaller and less demanding engine applications these

precision investment castings can be used to make integrally bladed disks.

As previously mentioned, ring rolling and shear spinning are also finding

new uses today by General Electric to produce near-net-shapes. In- many cases material input reductions of 50% and more can be made with cost savings ranging

from a few hundred to several thousand dollars per part.

In the 1960's, the Aircraft Engine Group began working with nickel-based

superalloy powder metals. This is an extremely complex technology with many

possible process variations. Manufacture of powder can employ rotating electrode,

rotating disk, and commercial rapid solidification gas atomization techniques, to name just three. Containers into which the powder is placed for consolidation can be made of glass, ceramic, sheet or thick metal dies. Densif ication has been

performed by direct hot isostatic pressing, extrusion, furnace consolidation at

atmospheric pressure and direct forging. The first three consolidation techniques

mentioned have also been combined with subsequent forging or rolling operations.

In addition to the nickel-based superalloys, we at GE have also worked with

titanium powders. Currently, we are working under Air Force contract to establish

today's cleanest production powder technique.

As demonstrated by our NASA' "Materials for Advanced Turbine Engine" contract

work, completed in 1979, typical Rene 1 95 input material reductions for powder

metal processes are 50%. Cost reductions indicated by this work were 35-40%, versus conventional forgings of the same alloy. Original projections of total

payoff were $8-10 million per year. However, as with the current titanium

powders, cleanliness became a major concern. Increased quality control measurements

imposed, significantly altered these projections. To realize the total material

and cost benefits that can be derived from direct hot isostatic compaction of

powder metals, additional development is required. The powder metal potential is

enormous, but realizing the entire near-net-shape objective remains a future target

for the aerospace industry.

P33-2
-3-

Hot die and isothermal forging are also part of the industry arsenal of

near-net-shape techniques. Today these processes can hold closer tolerances

than hot isostatically compacted parts and are cost competitive. Either of these

forging processes can be employed on conventional ingot product as well as with

powder consolidation, as mentioned previously. However, all desired configurations

cannot be forged to the nearest-net-shapes.

Coit benefits comparison of the various near-net-shape processes is a terribly complex issue. General Electric is now involved in an Air Force sponsored

effort to establish near-net-shape process mathematical models. Each of the

technologies mentioned has its specific advantages and limitations over the

others, depending on part size and geometry, as well as the type of material,

but information in this arena is rather limited. In order to determine the

feasibility of a given near-net-shape process and the economics of alternatives,

this program addresses the need for a data base of part geometry, function,

materials, tolerances and costs. Several aerospace companies are participating

in this Air Force work.

Like steak versus spare ribs, near-net-shapes cost more per pound than

conventional products - but the advantages in overall economics are enormous.

The actual per shape cost is less and processing cost as well as facility

requirements are dramatically reduced. Implementation of near-net-shapes

technology should be a major tool for addressing the intent of our National

Materials Policy.

J.S. Mosier

P33-3
OUTLOOK FOR AS- HIP' ED NEAR NET SHAPES

John Hoi 1 Colt/Crucible Research Center

P34
OUTLOOK FOR AS-HIPED NEAR-NET SHAPES

by

J. H. Moll*

Presented

at

Workshop on Conservation and Substitution

Technology for Critical Materials

Nashville, Tennessee

June 15-17, 1981

Technical Director, P/M and Welding, Crucible Research Center
OUTLOOK FOR AS-HIPED NEAR- NET SHAPES

ABSTRACT

Within the last decade, a powder metallurgy (P/M)

process has emerged which offers marked savings of critical

materials and energy. The process involves the use of prealloyed powders, near-net shape technology, and hot-isostaticpressing (HIP) . The application of this technology to tool

steels, superalloys and titanium alloys are discussed. The

application of this technology to tool steels has resulted

in materials which use less critical materials and perform

more efficiently. P/M superalloy turbine engine hardware

is currently in production as near-net shapes. The result

has been a reduction in critical input materials as well as

energy savings. The development of P/M titanium near-net

shapes is currently in progress. The technology promises

a marked reduction in the amount of titanium required to

produce airframe and engine hardware.

P34-2
OUTLOOK FOR AS-HIPED NEAR- NET SHAPES

Introduction

Conventional processing of metals often results in considerable waste of material and energy. As a result, there is

a need throughout industry for the direct production of net or

near-net parts. This is particularly important in the production of high speed tool steels, superalloys and titanium alloys

which contain high concentrations of critical elements such as

cobalt, chromium, tantalum and titanium. More efficient use of

these materials is necessary.

While powder metallurgy (P/M) technology has existed for

many years , it is only in recent times that P/M has been applied

to produce shapes of tool steels, superalloys and titanium in an

effort to conserve materials which are in short supply. A

unique P/M process has been developed to produce near-net parts.

This process involves hot-isostatic-pressing (HIP) of powderfilled shaped containers. In addition to material savings, this

as-HIPed product offers other benefits such as greater uniformity

of product, property advantages of finer structures, and fewer

finishing operations.

P/M Shape Process

Figure 1 shows the Crucible P/M process for making shapes

from metal powders. Tool steels and superalloys are gasatomized. In this process, high pressure gas is used to atomize

a molten stream of air or vacuum induction melted metal. The

resulting powder falls into a liquid gas quench at the base of

the chamber. The spherical nature of this powder, Figure 2,

is ideal for producing shaped P/M parts. Subsequent processing

of the powder involves screening and blending to obtain a uniform

size distribution.

P34-3
The processed powder is subsequently loaded into shaped

containers. Two basic types of containers are currently used,

steel and ceramic. Production containers are made from metal

and may be produced from welded pipe to produce simple cylindrical shapes. More complicated shapes may be produced from

low-carbon or stainless steel sheet. A process for making

very complex shapes using a ceramic mold is currently being

developed. Ceramic molds are made by a process similar to the

lost wax process. An oversize wax and/or plastic pattern,

Figure 3, can be made by machining or injection casting. After

a series of ceramic dip coatings, dryings, dewaxing and firing,

the ceramic mold is ready for powder filling, Figure 4.

Once metal containers are fabricated and cleaned, they

are loaded with powder, evacuated and sealed. Ceramic containers are loaded with powder, placed in an outer steel can

and surrounded by a secondary pressing media, Figure 5, and

then evacuated and sealed.

The final step in the P/M shape process utilizes hotisostatic-pressing (HIP) . Sealed containers are placed in an

autoclave, heated to temperatures ranging from 1600°F to 2200°F,

depending upon the alloy, and pressed under 15,000 psi gas

pressure. The result is a fully dense product. Figure 6 shows

the wide variety of shapes which can be produced by the P/M

process

.

The process for producing P/M titanium alloy shapes is

similar to that described for tool steels and superalloys except

that powder is produced by the rotating electrode process of

Nuclear Metals, Inc., Figure 7. A tungsten-arc or plasma-arc

provides localized melting at the end of a titanium alloy bar

while the bar is rapidly rotated. The rotating motion of the

bar spins off molten particles which subsequently solidify in

the enclosing evacuated chamber. The resulting powder is

spherical, Figure 8, and similar to gas-atomized powder.

P34-4
P/M Tool Steel Shapes

Tool steel products made from gas-atomized powder have

been in production for more than ten years. These materials

offer a number of advantages over their conventionallyproduced counterparts. These include the following*-^ :

(1) Superior grindability

.

(2) Improved toughness.

(3) Cross-sectional uniformity of hardness.

(4) More uniform size change.

Tool steels are highly alloyed materials, often containing substantial quantities of critical elements such as chromium and

cobalt. Table I gives compositions of several highly alloyed

tool steels which are currently produced by the powder process.

In addition to improved performance, the P/M process offers

the ability to conserve critical materials by producing as-HIPed

shapes. Figure 9 shows a pressed-to-shape hollow bar. This

bar was produced using concentric low-carbon steel pipes formed

into a powder container. Hollow bars can be produced to nine

feet in length and three-and-one-half feet in outside diameter.

Typical applications include cutting tools, punches, shafts,

broaches, and tube drawing preforms. Using conventional ingot

technology, hollow shapes would be made by metal working and/or

machining

.

Tool material savings can also be achieved through the use

of composite and near -net shapes made by the P/M process.

Figure 10 shows a shaper cutter blank made by bonding M2 tool

steel to the outside diameter of a carbon steel core. With

this technique, the highly alloyed material is used only where

required (i.e., at the outside cutting surface). Figure 11

shows a near-net shape hob produced from tool steel powder

using the ceramic mold process.

P34-5
P/M Superalloy Shapes

Superalloys are widely used in turbine engines. These

alloys, normally nickel or cobalt based, contain substantial

quantities of critical materials such as chromium, cobalt,

titanium, and in some instances, tantalum. Table II gives

the critical element content of a number of widely used alloys.

Hardware produced from these alloys typically exhibits a high

"buy-to-fly" ratio, often as high as 20:1. A marked reduction

in input material can be achieved by P/M shape technology.

Figure 12 compares the processing sequences used for a P/M

shaped engine shaft and a conventional cast and wrought engine

shaft. The savings in starting material, number of processing

steps, and machining can be noted. Figure 13 shows the

as-HIPed engine shaft and the detail that can be made with

P/M.

P/M superalloy hardware is currently being produced from

powder to near-net sonic shapes using metal containers by

Crucible Compaction Metals. These range from relatively

small turbine disks. Figure 14, to large turbine components,

Figure 15. An Air Force-sponsored P/M program' y is currently

in progress to reduce the input weight on a large, 32-inch

diameter, turbine disk for Pratt & Whitney Aircraft's JT9D

engine, Figure 16. The current input weight for this part

is 800 lb. To date, work under the program has reduced the

input weight to 550 lb. Further weight reductions of 40-50

lb are planned.

The P/M process can also be utilized to produce multicomponent parts. Using current technology, engine spools are

normally assembled from parts made from several individual

forgings. With the P/M shape process , the spools can be made

as a single piece. The result is a marked reduction in input

weight and the elimination of a number of processing steps.

P34-6
A sectioned container for a complicated spool is shown in

Figure 17. In this instance, the spool is comprised of six

segments: a shaft at the top, 4 compressor disks, and a bolt

flange on the bottom. The total input weight of individual

components is 490 lb. Made as a single component, the total

weight is 210 lb; a material savings using P/M multicomponent technology of 280 lb per engine.

Parts produced by the P/M HIP process are fully dense

and mechanical properties compare well with forgings and meet

specification or target requirements. For Rene 95, cut-up

test specimens for many disks show the strength and ductility

levels and the statistical deviations in room- and elevatedtemperature properties to be excellent, Table III. The

1200°F rupture and creep properties also meet specification

requirements. MERL 76 as-HIP tensile properties, Table IV,

meet strength and ductility goals set in an Air Force pro-

( 2 ) gram' '

.

P/M Titanium Alloy Shapes

P/M titanium is newer and not as far advanced as tool

steels and superalloys. An intensive effort is currently in

progress to develop the ceramic mold process for producing

near-net engine and airframe hardware from titanium alloy powder.

(2) Initial studies'- ' were conducted using relatively small parts

such as the keel splice former shown in Figure 18. The conventionally forged part weighs 4.67 lb whereas the HIP nearnet shape weighs about 1.0 lb. In addition to materials

savings, analysis, Table V, shows an energy savings using

the P/M process for near-net titanium alloy parts.

Excellent progress is being made in a current Air Force/

Crucible manufacturing technology project aimed at producing

large titanium airframe parts and complex engine parts. The

target near-net parts being made in this program are listed in

Table VI. Considerable material, machining and production

time can result from the P/M near-net shape process.

P34-7
The following are several different types of as-HIPed

Ti-6A1-4V airframe parts:

(1) A drop-out link for the McDonnell-Douglas F-15

fighter, Figure 19, is a large, deep-pocketed

part typical of many titanium airframe parts.

The weight of the as-HIPed part is 54 lbs

compared to a forging weight of 94 lbs.

(2) The Northrop arrestor hook support fitting for

the F-18 fighter, Figure 20, is the largest P/M

part made to date. The weight of this as-HIPed

first trial part was 60 lb compared to a forging

weight of 175 lbs.

(3) The Boeing walking beam support fitting for the

747 landing gear, Figure 21, represents another

type of airframe titanium shape. The as-HIP

weight is 30 lbs. The forging weight is 50 lbs.

The program also involves several P/M Ti-6A1-4V engine

parts which include the following:

(1) Figure 22 shows a compressor spool for General

Electric's TF34 engine. The as-HIPed weight,

including an added test ring, was 70 lbs. The

forging for this part weighs 104 lbs.

(2) The Williams Research compressor rotor for the

F-107, Figure 23, shows that thin complex blades,

attached to the base, can be made by the ceramic

mold process. The part is currently machined from

a pancake forging weighing 30 lbs. The as-HIPed

weight is 5.5 lbs.

P34-8
The properties of P/M as-HIPed Ti-6A1-4V meet many

current specifications. Table VII compares the properties

of as-HIPed standard composition powder with requirements of

AMS 4928H^). Tensile properties meet specification requirements in different test directions. Good fracture toughness

is also indicated. Properties of as-HIPed Ti-6A1-4V made

from extra low interstitial (ELI) powder, Table VIII, compare

favorably with typical wrought mill annealed material and

readily meet MMS-1225 specification properties^). Excellent

fracture toughness values, Kq, have also been observed.

As-HIPed near-net parts have also been produced from

Ti-6Al-6V-2Sn alloy powder. This process was developed at

Crucible Research Center and is currently being applied and

tested for various specific applications under Navy sponsorship at Grumman. One of these involved a fuselage brace for

the F-14A aircraft^). Figure 24 shows a pilot production

lot of these braces ready for shipment to Grumman. Work is

currently in progress, under Navy sponsorship, to produce a

large, 48-inch, nacelle frame using as-HIPed P/M Ti-6Al-6V-2Sn

shapes^). The frame, Figure 25, will be HIPed as four

individual components which will subsequently be joined by

electron beam welding to produce the final nacelle frame.

Summary

Conventional manufacturing procedures often use excessive

material and energy to produce final parts. A P/M near-net

shape process has been developed to reduce input material and

conserve critical materials. The process involves hotisostatic-pressing (HIP) of powder-filled shaped containers.

Shaped parts are currently in production for tool steels and

superalloys using steel containers. Complex tool steel,

superalloy and titanium shapes are being developed using a

ceramic mold process. The properties of fully dense as-HIPed

shapes generally meet or exceed those of conventional cast

plus wrought material.

P34-9
"The material contained in this paper is intended for general

information only and should not be used in relation to any

specific application without independent study and determination of its applicability and suitability for the intended

application. Anyone making use of this material or relying

thereon assumes all risk and liability arising therefrom."

P34-10
REFERENCES

(1) A. Kasak and E. J. Dulis , "Powder Metallurgy Tool Steels"

Powder Metallurgy , No. 2, 1978.

(2) "Manufacturing Process for Production of Near-Net Shapes

by Hot-Isostatic-Pressing of Superalloy Powder"

Air Force/Pratt & Whitney Aircraft Contract No.

F33615-77-C-5187.

(3) J. H. Schwertz, V. K. Chandhok, V. C. Petersen, and

V. R. Thompson, "Consolidation of Titanium Powder to

Near-Net Shapes" Final Report AFML-TR-78-41 , May 1978.

(4) V. C. Petersen and V. K. Chandhok, "Manufacturing Process

for the Hot-Isostatic-Pressing of Large P/M Shapes"

Interim Report AFML-IR-184-7T(I) , June 1979.

(5) G. Chanani, W. Highberger, C. Kelto and V. C. Petersen,

"Application of Titanium Powder Metallurgy for Manufacture

of a Large and Complex Aircraft Component" Powder

Metallurgy of Titanium Alloys , AIME , 1980

(6) R. Witt and J. Magnuson, "Flight Qualification of

Titanium F-14A Airframe Components Manufactured by

Hot-Isostatic-Pressing" Final Report, Contract No.

N0019-76-C-0143 , Naval Air Systems Command, June 1977.

(7) "Electron Beam Welded HIP Structures" Navy /Grumman

Contract No. N00019-80-C-0034

.

P34-11
Table I

COMPOSITION OF SEVERAL TOOL STEELS

MADE BY THE P/M PROCESS

(Weight %)

Alloy C W Mo Cr V Co

M2 1.0 6.0 5.0 4.0 2.0 - M4 1.3 5.5 4.5 4.0 4.0 - M42 1.1 1.5 9.5 3.7 1.5 8.0

T15 1.5 12.0 - 4.0 5.0 5.0

Table II

CRITICAL ELEMENT CONTENT

OF SEVERAL SUPERALLOYS

USED IN ENGINE DISKS

(Weight %)

Astroloy IN- 100 Rene 95 MERL 76 IN-718 Waspaloy PA-101

Chromium 15 10 14 12 19 19 13

Cobalt 17 15 8 19 - 14 9

Titanium 3 5 2.5 4 1.0 3 4

Tantalum - - N - - - 4

P34-12
Table III

CUT-UP PROPERTIES OF AS-HIP RENE 95

TURBINE DISKS a

Properties Spec Mean C

R.T. Tensile

Ultimate (ksi) 225.0 239.4 2.8

Yield (ksi) 163.0 176.9 3.5

Elongation (%) 10 17.2 1.9

Red. of Area (7») 12 20.5 1.8

1200 F Tensile

Ultimate (ksi) 205.0 220.1 5.4

Yield (ksi) 153.0 165.2 4.9

Elongation (%) 8 13.8 4.1

Red. of Area (%) 10 16.5 3.3

Stress Rupture*5

Life (hr) 50 88.8 26.3

Elongation (%) 3.0 6.5 2.1

Creep0

Time (hr

)

50 54.6 6.7

Elongation (7») 0.3 max .10 .08

aFirst 75 engine sets (150 disks).

b 1200 F/150 ksi.

c 1100 F/150 ksi.

Table IV

TENSILE PROPERTIES OF HIP MERL 76 POWDERa

Test Yield Ultimate Elonga- Reduction

Temperature Strength Strength tion of Area

(°F) (ksi) (ksi) (7.) (%)

Test Data

RT 158 226 17 19

1000 152 203 12 19

1150 154 213 12 15

1300 152 187 22 22

Target Properties

RT 154 223 15 15

1300 150 174 12 12

aHeat Treatment: 2125 F/l hr/1500 F salt quench +

1400 F/16 hr/air cool

P34-13
Table V

COMPARISON OF ENERGY REQUIREMENTS

FOR CONVENTIONAL FORGINGS AND

P/M AS-HIPED TI KEEL SPLICE FORMER

Process

Energy Requirements (kwh)

Conventional

Forging

P/M

Shape

Bar Product 301.7 72.7

Forging 1.8 - Atomization - .7

HIP - 52.0

Machining ,5 .1

Total 304,0 125.5

Table VI

WEIGHT COMPARISONS OF PARTS SELECTED

FOR P/M TITANIUM

SubContractor Part Alloy

Part Weight (lb)

Forging

HIP Final

Billet As-Forged Part

Boeing Walking Beam Support (747) Ti-6-4 (STD) 55 50 30 21 GD/Fort Worth Horizontal Stabilizer Pivot Shaft

(F-16)

Ti-6-4(ELI) 148 120 65 32

GE/AEG Compressor Spool 3-8

(TF-34 Engine)

Ti-6-4 (STD) 147 104 70 15

MCAIR Drop-out Link (F-15)

Keel Splice Former (F-15) , Near-Net Ti-6-4 (STD) 115

6 94

4.7

54 0.913.8

0.4

Northrop Arrestor Hook Support Fitting (F-18) Ti-6-4 (ELI) - 175 60 28.4 P&WA 3rd Stage Fan Disk (F-100 Engine) Ti-6-2-4-6 120 94 70 27 Williams

Research

Radial Compressor Rotor

(F-107 Gas Turbine)

Ti-6-4(STD) 32 30 5.5 3.6

P34-14
Table VII

ROOM TEMPERATURE TENSILE AND TOUGHNESS PROPERTIES

FOR HIP Ti-6A1-4V (STANDARD) POWDER

Condition

Orientation

Yield

Strength

(ksi)

Ultimate

Strength

(ksi)

Elongation

(%)

Reduction

of Area

(%)

W/Aa (in-lb/ in. 2)

Predicted

V

(ks i -/ItT.

)

As -HIP LT 135 142 12 40 410 63 HIP + Vacuum

Anneal

(1300 F/8 hr/

slow cool)

LT 132 139 13 38 565 73 TL 130 138 12 35 578 74 ST 132 139 12 36 541 72 AMS Spec

4928 H

120 130 10 15 - -

aTested in compression mode.

bPredicted from Kq2 /E - 0.57 (W/A)

Table VIII

ROOM TEMPERATURE

OF HIP

TENSILE AND TOUGHNESS PROPERTIES

Ti-6A1-4V (ELI) POWDER

Condition3

Yield

Strength

(ksi)

Ultimate

Strength

(ksi)

Elongation

(7.)

"q

(ksi Vin.

)

As -HIP 124 135 15 84

Beta Anneal 130 138 10 87

Recrystallize

Anneal 125 134 15 86

Mill Anneal 119 128 17 89

Typical

Wrought

(Mill Anneal)

115 125 12 -

MMS-1225

Spec (Annealed) 110 120 10 -

aAs-HIP - No heat treatment

Beta Anneal - 1300 F/12 hr (vacuum degassed) 1750 F/30 min.,

1865 F 15 min., air blast cool, 1300 F/2 hr/AC

Recrystallize Anneal - 1300 F/12 hr (vacuum degassed)

1759 F/2 hr/AC, 1400 F/2 hr/AC

(to below 900 F in 45 min.)

Mill Anneal - 1300 F/12 hr (vacuum degassed) 1300 F/2 hr/FC

(300 F/hr max) to 1000 F/AC

P34-15
Load

To Vacuum Pump

Hot Outgas

Figure 1. The Crucible P/M Superalloy Process.

Figure 2- Argon Gas-Atomized Powder.

P34-16
—— « 4 Figure 3. Plastic and Wax Patterns.

Figure 4. Ceramic Mold.

P34-17

108-80

567-81
r

Pressure weld

Outer metal

Container

Secondary pressing

'medium

Ceramic shell mold

Figure 5. Container Assembly for Ceramic Mold Process.

Figure 6. Variety of Parts Made by P/M Shape Process.

P34-I8

554-78
Figure 7. Rotating Electrode Process for

Making Titanium Alloy Powder.

Figure 8. Rotating Electrode Titanium Alloy Powder.

P34-19

581-81
CO

!"*

I

r^- vo

Figure 9. Hollow Bar Produced by P/M Process.

Figure 10. Composite Shaper Cutter Blank (Center

Outside Diameter - M2 Tool Steel)

.

Mild Steel,

P34-20
Figure 13. Large P/M Superalloy Engine Shaft Made Using Ceramic Mold Process.

Figure 14. Small P/M Turbine Disks Made Using Metal Container.

00

i onm

CM

P34-21

833-76
Figure 15. Large P/M Turbine Disk Made Using

Metal Container.

Figure 16. 32-Inch P/M Turbine Disk Made Using

Metal Container.

P34-22

148-81
00

o

CO

LO

Figure 17. A Sectioned Container for a P/M

Multicomponent Compressor Spool,

i

i Figure 18. Keel Splice Formers - (Left - forging,

Center - as-HIPed, Right - finished part)

.

P34-23

628-75
Figure 19. The McDonnell Douglas F- 15 Drop-Out

Link P/M Titanium Part.

Figure 20. The Northrop F-18 Arrestor Hook Support

Fitting P/M Titanium Part.

P 34-24

748-79

482^79
Figure 21. The Boeing 747 Walking Beam Support

Fitting P/M Titanium Part.

Figure 22. The General Electric TF-34 Compressor

Spool P/M Titanium Part.

P34-25

1019-79

1038-79
Figure 23. The Williams Research F-107 Compressor

Rotor P/M Titanium Part.

Figure 24. Grumman F-14A Fuselage Braces Made

from Ti-6A1-6V-2SN Powder

P 34-26

946-80

181-79
Figure 25. Large (48 inches x 40 inches) Nacelle Frames

to be Made from Electron Beam Welded as -HIP

Shapes using Ti-6A1-6V-2SN Powder.

P34-27
TECHNOLOGICAL OPPORTUNITIES TO MORE FULLY UTILIZE METALS

WITH DOMESTIC SOURCES OR NEAR DOMESTIC SOURCES

AND SUBSTITUTES FOR CRITICAL METALS

Horace N. Lander

Climax Molvbdenip Co,

P35
KEYNOTE ADDRESS

"Technological Opportunities to More Fully Utilize Metals

with Domestic Sources or Near Domestic Sources as

Substitutes for Critical Metals"

Keynote Address for the Session

by

Horace N. Lander

Senior Vice-President, Research and Development

Climax Molybdenum Company

a Division of AMAX Inc.

INTRODUCTION

Welcome to the session with the longest title! As keynoter

and chairman, I realize that by the time I explain the title, my

time will be up and we can hear the speakers tell us how four

metals readily available in the United States can substitute at

least partially for four metals that could be unavailable at a

future time because of some geopolitical crisis. You have

attended several sessions in which critical materials have been

defined, and sessions in which the speakers have reviewed techniques

to reduce the use of critical materials. Our task in this session

is to call your attention to four versatile alloying elements, and

how best to utilize them to provide substitute materials that will

perform as well as the materials highly dependent on more critical

alloying elements.

SLIDE 1

P35-1
2 /

Let us look again at the now very familiar bar chart defining

U. S. reliance on imported metals. First of all, it is obvious

that the critical metals are titanium, tantalum, chromium and

cobalt. Manganese is also critical, but is not considered as

serious as the other four because it is abundant in many areas of

the world except North America, and it is considered unlikely that

suppliers in all of the areas would limit their exports at the same

time

.

Next, it is evident that nickel, tungsten, vanadium and

molybdenum are much less dependent upon imports. In fact, if we

recognize Canada as the most reliable "foreign" source, then our

import reliance from other sources is 30 percent or less for these

four metals. For this reason, the present session will concentrate

on the opportunities to use these four available elements (Ni, W,

V, Mo) to substitute at least partially for these four critical

elements (Ti, Ta, Cr, Co).

We shall ask the speakers, who are experts on nickel, tungsten,

vanadium and molybdenum, to bring us up-to-date on the availability

of these metals and the success to this point in efforts to use

these metals as substitutes for titanium, tantalum, chromium and

cobalt. I believe it can be a useful first step, however, to

define alloy substitution, to take a realistic look at the various

steps in the substitution process, and to discuss the stimulus

for substitution.

P35-2
3 /

STIMULUS FOR SUBSTITUTION

SLIDE 2

We shall deal with two major stimuli for alloy substitution --

to achieve an economic gain, or to accomplish a national strategic

goal. Let us first deal with strategic substitution.

SLIDE 3

The factors involved in strategic alloy substitution, to

reduce our dependence on alloys available from potentially

unstable countries, are, first, the reliability of the various

external supply sources. For many imported metals, the external

sources are quite stable and reliable, and probably will remain

that way. Reliability must be assessed in terms of geopolitical

factors, usually by the federal government.

The other principal factor involved in strategic alloy

substitution is the effect of disrupted metal supply. Disruption

v should be considered in terms of both the effect on the national

defense capability, as well as the effect on the total economy.

SLIDE 4

P35-3
4 /

In terms of the defense capability, even if technically

adequate substitutes are not available, only a relatively small

amount of total metal supply may be needed to satisfy defense

needs. Because of these relatively small supply requirements for

defense, a stockpile program is feasible, if it is limited to

defense requirements. We could spend a great deal of time

examining our past stockpile policies, but that is not our task

today. For purposes of our discussion it is safe to assume that

a defense stockpile of critical materials may be needed until

fully adequate substitutes are available.

SLIDE 5

In terms of the total economy, however, stockpiles are not

the answer. First let us assume that disruption of critical

material supply is not caused by armed conflict, but by political

action on our part or on the part of those who would supply us

with the material. The results can be the same as we saw

recently in the cobalt crisis -- high prices and short supply.

The national response is to use technically adequate substitutes, even those that under normal conditions would not be

economical. It would be unwise to invade a defense stockpile in

response to political actions, except for strictly defense requirements .

I would like to make the point here that cartels involving

critical metals are much less likely if adequate substitutes

have been identified and well publicized.

P35-4
5 /

SLIDE 6

Now let us examine the goal of economic substitution -- and

the various steps in this process that are going on all the time.

First of all, the substitute material must exhibit acceptable

properties at a lower cost, or improved properties at a cost that

can be justified in terms of a better product that can be sold at

a premium, or in terms of lower processing cost. It is important

to factor into the total cost of substitution the cost of

innovation -- that is the cost of several steps required to

demonstrate the adequacy of a substitute -- as well as the

amortized cost of transition from the standard material to the

substitute material.

SLIDE 7

Innovation is classically based on these four steps --

foundation, invention, demonstration and implementation. Let us

examine each of these in terms of development of a substitute

alloy.

SLIDE 8

First there must be the foundation of basic metallurgical

knowledge. Without this, innovation cannot be expected to be

successful except in the case of a few "lucky breaks", and such

technical gambling is very costly.

P35-5
6 /

For purposes of material substitution, supplemental knowledge

may be required to meet specific requirements. It is usually not

possible to design an alloy on the basis of metallurgical theory

alone -- the response to environment, such as heat or corrosion,

for example, often cannot be predicted.

SLIDE 9

Invention is the next step, after considering the requirements

of a material in terms of the knowledge available. Here we are

not talking about revolutionary invention — the great inspirations

that create new industries, but evolutionary invention -- organized to take advantage of available knowledge to create

a competitive advantage or to respond to a specific need.

Materials substitution is based on evolutionary invention and

results in laboratory demonstration that the new material exhibits

the required properties.

SLIDE 10

Successful materials development requires several levels of

demonstration beyond the laboratory -- field trials of small

heats, followed by full-scale production trials, and finally

rigorous product qualification.

Implementation usually overlaps demonstration in a successful

materials development. Marketing often begins at the field trial

stage and, to be successfully implemented, the new material must

have product acceptance by one or more producers and several

consumers

.

P35-6
7 /

SLIDE 11

Once a proven substitute material has been developed,

there is a considerable transitional cost before the theoretical

savings can be realized. This slide describes the various initial

costs that must be incurred. The cost of production trials,

product qualification and marketing have already been discussed.

In addition are the costs of field service to help customers with

the transition, and the inevitable double inventory of standard

and new material during the transition.

Whether the alloy substitution is for economic or strategic

reasons, the steps are the same. In the case of economic substitution the net result is a realized savings at some future

time, as shown here. In the case of a strategic substitution,

the substitute alloy may never result in a savings over an

existing alloy. In such a case the stimulus for the development

cannot be expected to come from the private sector.

Now let us examine the technical considerations of alloy

substitution

.

METALLURGY OF SUBSTITUTION

SLIDE 12

As shown in this slide of the periodic table, the four transition

elements upon which this session is focused are neighbors of the

four critical metals titanium, chromium, cobalt, and tantalum.

P35-7
8 /

However, it is not direct substitution of one element for

another that we are considering, because the essential factor

is that the substitute provides the important functional properties of the original. For example, yesterday we heard that

the substitution for chromium in austenitic stainless steels

is not its replacement with, say, molybdenum; rather it is

another alloy combining several metallic elements including

manganese and aluminum. Such a substitution may require a long

development and transition time. Other substitutions under

development to reduce the level of chromium in stainless steels

by increasing the molybdenum level have already reached the production trial stage and therefore require a shorter transition

time. The substitute must perform the same function as the

original, only if the substitute has the same properties as the

original is the replacement technically adequate.

SLIDE 13

A very limited number of applications require a material

with only one critical property. In every other case, a

hierarchy of property requirements must be realized by tVie alloy.

This makes the substitution more challenging, but far from impossibl

The expanded use of the four versatile alloying elements which

we are about to consider offers many opportunities to achieve a

broad range of properties in various alloy systems. It is the

multitude of properties that vanadium, nickel, molybdenum and

tungsten impart to alloys that make them so attractive as

substitutes

.

P35-8
9 /

When a designer makes a material selection, he considers more

than the required properties of the material. The metallurgy of

substitution also consists of the processing route taken to build

the final product. Two levels of change may be identified

relative to the processing of an alloy.

SLIDE 14

First is the process employed to make the alloy. There is

no reason to expect that a substitute alloy will be made in the

same manner as the original. Existing processes may require

modification to be compatible with the substitute alloy, or the

existing process may be completely incompatible. But an opportunity

exists that by changing the original process, the critical metal

may be conserved and the necessity for substitution thereby

mitigated. The example of the development of argon-oxygen decarburization and its attendant improvement in yield of chromium comes

immediately to mind.

The second implication for processing is to use processing

itself to conserve material. Recent advances in such processes

\ as thermomechanical treatments, near-net shape forming, ion

implantation, and laser glazing permit the manufacture of novel

new metallurgical microstructures. Further developments in these

and other areas are certain to open new opportunities for processing as a means for conserving materials and alloying elements.

STATISTICS OF CURRENT USAGE

SLIDE 15

The subject of this session is, however, the expanded use of

metals with domestic or near-domestic sources as substitutes for

P35-9
10 /

critical metals. In closing this introduction to the session

I shall briefly highlight some of the statistics of current usage

of the four elements of interest. In the slides which follow I

have used U.S. Bureau of Mines data for 1979. I expect that the

five speakers will elaborate on these data and provide even

more current information.

SLIDE IS

The four alloying elements have long been used by alloy

designers in the United States. This fact has led to the many maj

end uses, illustrated in this slide. While there is some overlap

in the categories and some unexpected gaps, the important point

is the breadth to which each element is used in the current

U.S. economy. The four elements are used principally in the

producing sector of the economy rather than in consumer goods.

It is this sector which will largely be called upon to absorb

the effects of any reduction in critical metal supply, and the

familiarization of this sector with the domestic and neardomestic substitutes assures a minimum of disruption during

required alloy changes.

Because the four alloying elements have long-established uses,

large business enterprises have been built to produce, refine and

distribute them. The two elements whose use in dollar terms are

greatest, nickel and molybdenum, have been aided in their growth

P35-10
11 /

by active metallurgical research and development for many years.

The principal companies involved in the vanadium and tungsten

businesses have more recently begun similar programs of technical

support. Thus, the four domestic and near domestic alloying

elements have a distinct further advantage of a fully constructed

business infrastructure plus metallurgical expertise to facilitate

expanded applications.

SLIDE 17

Most of the U.S. consumption of molybdenum and vanadium, and

substantial percentages of nickel and tungsten is in the

steel industry. This slide illustrates, as the one before, the

wide range of intermediate products into which the elements are

already incorporated. The specific applications reported here

for 1980 represents only one particular set of technological and

economic conditions. As the country’s economy changes and,

importantly, as technology advances, the distribution of usage by

intermediate product changes. Such changes are an ordinary part

of the metals business, so increased reliance on these metals as

substitutes for the critical metals will not constitute a unique

situation. I m sure the speakers to follow will elaborate further

on the directions that the domestic and near-domestic alloying

elements are expected to take.

SLIDE 18

P35-11
12 /

This slide is intended to illustrate the relative sizes of the

production and use of the four metals in the United States. Only

in molybdenum is the United States presently self sufficient. The

share of imports of nickel and tungsten from Canada is very large,

however, and when this source is included the net import reliance

is reduced to the range of 22 to 35 percent. This may appear to be

an unacceptably high reliance on imports but the reserves of these

four metals in the U.S. and near-domestic areas are very large.

SLIDE 19

Just a reminder that according to the Bureau of Mines

a Reserve Base is a "resource that meets minimum physical and

chemical requirements of current mining and production practice"

and is likely to be economically available within a long-term

planning frame. It included identified reserves that are both

currently economic and marginally economic.

SLIDE 20

When the reserve bases of the four metals are considered

it is obvious that the metals are plentiful domestically and

near-domestically . Furthermore, there is no threat that the

supply of these metals may be rapidly depleted if their use expands

markedly. The four are truly abundant in North America and can

be relied upon for many years of future utility.

SLIDE 21

P35-12
13 /

A combination of factors supports the notion that critical

metals may find molybdenum, nickel, tungsten, and vanadium as

excellent substitutes. These factors include: the natural

abundance of the four, their versatility as alloying elements,

their long-standing use by the technological community, and the

existance of a business infrastructure for the mining, refining,

distribution, and technological development of each. It is worth

repeating that private industry can be expected to pursue substitutions

only if there is potential economic gain. Efforts to find substitutes

for metals considered critical, but which are currently readily

available, will require stimulus from the federal government.

Our attention will now be turned to the technological opportunitites

that each of the four metals offers. The speakers will be focusing

on two major areas.

SLIDE 22

First, they will provide you with greater detail on the

metal statistics of molybdenum, nickel, vanadium and tungsten.

And secondly, they will cite progress which has already ^>een

achieved in the effective use of molybdenum, nickel,

vanadium, and tungsten to reduce our dependence on chromium,

cobalt, titanium, and tantalum.

P35-13
United

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P35-14

SLIDE

1
ALLOY SUBSTITUTION

• ECONOMIC

• STRATEGIC

P35-15

SLIDE 2
FACTORS INVOLVED IN STRATEGIC

SUBSTITUTION TO REDUCE DEPENDENCE ON

EXTERNAL SUPPLY

•RELIABILITY OF EXTERNAL SUPPLY

(GOOD EXCEPT FOR A FEW METALS)

•EFFECT OF DISRUPTION ON

- DEFENSE CAPABILITY

-TOTAL ECONOMY

SLIDE 3

P35-16
CRITICAL MATERIALS

AFFECTING DEFENSE CAPABILITY

TECHNICALLY ADEQUATE SUBSTITUTES MAY

NOT BE AVAILABLE, BUT ...

- TOTAL MATERIAL REQUIRED IS SMALL

- STOCKPILE PROGRAM FEASIBLE

SLIDE H

P35-17
MATERIALS DISRUPTIONS

vs

TOTAL ECONOMY

POLITICAL ACTIONS:

- HIGH PRICE

-SHORT SUPPLY

NATIONAL RESPONSES:

- USE TECHNICALLY ADEQUATE

SUBSTITUTES EVEN IF UNECONOMIC

- DO NOT USE DEFENSE STOCKPILE

SLIDE 5
ECONOMIC SUBSTITUTION

• ACCEPTABLE PROPERTIES

• LOWER TOTAL COST MUST INCLUDE:

- COST OF INNOVATION

- AMORTIZED COST OF TRANSITION

SLIDE 6

R35-19
STEPS

TO INNOVATION

• FOUNDATION

• INVENTION

• DEMONSTRATION

• IMPLEMENTATION

SLIDE 7

P35-20
FOUNDATION

• AVAILABLE BASIC METALLURGICAL KNOWLEDGE

• SUPPLEMENTAL KNOWLEDGE TO MEET SPECIFIC

REQUIREMENTS OF SUBSTITUTION

SLIDE 8

P35-21
INVENTION

• REVOLUTIONARY - NOT IN RESPONSE TO SPECIFIC NEED,

BUT CAN CREATE NEW INDUSTRIES

® EVOLUTIONARY - ORGANIZED TO CREATE COMPETITIVE

ADVANTAGE OR TO RESPOND TO SPECIFIC NEED

• MATERIALS SUBSTITUTION BASED ON EVOLUTIONARY

INVENTION, AND RESULTS IN LABORATORY

DEMONSTRATION OF ADEQUATE PROPERTIES

SLIDE 9

P35-22
DEMONSTRATION

FIELD TRIALS

FIRST FULL-SCALE PRODUCTION TRIALS

PRODUCT QUALIFICATION

IMPLEMENTATION

MARKETING

PRODUCT ACCEPTANCE

SLIDE 10
COST/TON

ECONOMICS OF TRANSITION

IN ALLOY SUBSTITUTION

INVENTORY

FIELD SERVICE

MARKETING

PRODUCT QUALIFICATION

PRODUCTION TRIALS

THEORETICAL

SAVINGS

REALIZED

SAVINGS

EXISTING

ALLOY

.SUBSTITUTE

ALLOY

TIME

SLIDE 11

SOURCE: DAVISON

P35-24
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P35-25

SLIDE

12
METALLURGY OF SUBSTITUTION

IN ALLOY SYSTEMS

• RELATIVELY EASY WHEN CONSIDERING ONE PROPERTY

AT A TIME

© MORE DIFFICULT TO PROVIDE ALL REQUIRED PROPERTIES:

- STRENGTH AT ROOM AND SERVICE TEMPERATURE

- TOUGHNESS AT ROOM AND SERVICE TEMPERATURE

- FATIGUE RESISTANCE

- CORROSION RESISTANCE

-WELDABILITY

- FORMABILITY

- ETC.

SLIDE 13

P35-26
IMPLICATIONS FOR PROCESSING

• MODIFY PROCESSING TO OPTIMIZE ALLOY CHANGES

• USE NEW PROCESSES TO CONSERVE ALLOYS

SLIDE M

P35-27
STATISTICS OF

CURRENT USAGE

©MOLYBDENUM

©NICKEL

©VANADIUM

©TUNGSTEN

SLIDE 15

P35-28
MAJOR END USE DISTRIBUTION IN THE U.S.

(Percent in 1979)

Mo Ni V W

Machinery and Metalworking 32 30 77

Transportation 22 24 34 10

Oil and Gas Industry 17

Chemical Industry 13 14 5

Electrical Industry 8 13 4

Construction 9 19

Consumer Goods 16

Lamps and Lighting 6

Other 8 24 12 3

100 100 100 100

Approximate Value,

Million 1979 $ 500 1470 94 200

SLIDE 16

P35-29
U.S. CONSUMPTION BY INTERMEDIATE PRODUCT

(Percent in 1979)

APPLICATION ELEMENT

Mo Ni V W

STEELS

Carbon and HSLA 8

- 53 - Stainless and Heat Resisting 15 36 - 2

Full Alloy 40 10 23 1 Tool 6 - 12 10

CAST IRONS 5 2

- - SUPERALLOYS 8 8

- 4

OTHER ALLOYS 2 27 9 4

MILL PRODUCTS 7

- - 22

CHEMICALS AND CERAMICS 6

- 1 3

PLATING - 15 - - CARBIDES - - - 52

MISCELLANEOUS AND UNCLASSIFIED 3 2 2 2

100 100 100 100

TOTAL 1979 USE, MILLION LBS 74 543 15.5 25.5

SLIDE 17

P35-30
1979 U.S. PRODUCTION, IMPORTS AND EXPORTS

(IN MILLION POUNDS OF METAL)

Mo Ni V W

Mine Production 141 28 12.6 6.6

Imports for Consumption 2 390 4.6 11.0

Exports 68 42 2.8 1.4

Net Import Reliance, % 0 77 25 59

Net Import Reliance

Excluding Canada, % 0 22 25 35

SLIDE 18

P35-31
RESERVE BASE

(AS DEFINED BY U.S. BUREAU OF MINES)

“RESOURCE THAT MEETS MINIMUM PHYSICAL AND

CHEMICAL REQUIREMENTS OF CURRENT MINING

AND PRODUCTION PRACTICES”

- INCLUDES CURRENTLY ECONOMIC (RESERVES)

AND MARGINALLY ECONOMIC (MARGINAL RESERVES)

SLIDE 19

P35-32
RESERVE BASE

(IN MILLION POUNDS OF METAL)

COUNTRY OR REGION

United States

Canada

Mexico

Chile

Other South America

Pacific

Europe

Republic of South Africa

Other Market Economy Countries

Central Economy Countries

World Total

1979 U.S. Consumption

Mo Ni V W

9,100 5,400 230 275

1,100 17,200 - 535

- - - 44

5,400 - 300 - 500 - - 127

30,000 400 410

- - - 264

- - 17,200 - 600 56,000 700 180

2,000 16,400 16,000 3,700

18,700 125,000 34,800 5,600

74 543 15>5 25.5

P35-33

SLIDE 20
SESSION GOALS

• PROVIDE MORE DETAIL ON METAL STATISTICS

• CITE PROGRESS IN EFFECTIVE SUBSTITUTION OF

Mo, Ni, V, W

TO REDUCE DEPENDENCE ON

Or, Co, Ti, Ta

SLIDE 22

P35-34
SUPPORT FOR SUBSTITUTION

• PRIVATE INDUSTRY IF CURRENT OR

POTENTIAL ECONOMIC GAIN

• FEDERAL GOVERNMENT IF MATERIALS

DISRUPTION POSSIBLE, BUT NO ECONOMIC

GAIN ENVISIONED

SLIDE 21

P35-35
MOLYBDENUM AS A SUBSTITUTE FOR CRITICAL METALS

Ralph M. Davison

Climax Molybdenum Co.

’ P36
MOLYBDENUM AS A SUBSTITUTE FOR CRITICAL METALS

Ralph M. Davison*

INTRODUCTION

Molybdenum is readily available in ample supply from domestic and neardomestic sources. It is technically versatile and the technology of its utilization

is well known. Molybdenum can make a major contribution to reducing dependence of

this nation on critical metals.

SUPPLY AND DEMAND FOR MOLYBDENUM

Since its first use for armor and armaments in World War I, molybdenum

has grown to be an important alloy element in use worldwide in a wide diversity of

products. As shown in Table 1, it is used in all industrialized countries with the

extent of its use in rough correlation to the degree of industrial development.

Growth in the use of molybdenum has outpaced overall economic growth for over fifty

years, and it is expected that it will continue to do so for the foreseeable future.

Worldwide requirements for molybdenum are presently slightly over 200 million

pounds per year except in recession periods, with the United States requirement

being roughly 70 million pounds.

Molybdenum is a product of the Western hemisphere, as shown in Table 2, with a

predominant concentration in the United States and with Canada having the second

largest share. Commercially, molybdenum is mined either as a primary product or as

a by-product or co-product of copper mining. Mine capacity has increased rapidly

over the last five years in response to market demand, Most of the increase has been

in new primary mines, a factor that will assure molybdenum supply in the future.

As shown in Table 3, the dominant position of the United States, and even more the

combined dominance of the United States and Canada, will increase in the future.

The tight supply of the late 1970’s prompted new mine development which will result in

*Dr. R.M. Davison is Director of Metallurgical Development, Climax Molybdenum Company,

P.0. Box 1*568, Ann Arbor, MI 48106

P36-1
- 2 -

an increase of about 30 percent in mine capacity by 1983. These new mines are all

in North America, owned and operated by commercial companies, and are in most

cases, primary molybdenum mines. As indicated in Table 4, these trends are expected

to continue as the properties known to exist and to be in evaluation are similar

in nature and location.

APPLICATIONS OF MOLYBDENUM

Molybdenum is a highly versatile and effective alloy element. In additions

under 1 percent, but typically between 0.2 and 0.4 percent, molybdenum provides

hardenability in steels and irons. Not only is molybdenum 3 highly efficient

hardenability agent in terms of weight or atomic percent, at the same time it

enhances the toughness of the hardened steel. Molybdenum's contribution of

resistance to tempering and to temper embrittlement allows the hardened steel to

be used at elevated temperatures without degradation of properties. Molybdenum

provides strengthening both through solid solution strengthening and through

precipitation hardening in steels and alloys. Molybdenum in amounts typically

ranging from 0.5 to 6 percent, but as high as 26 percent enchances the corrosion

resistance of steels and alloys. Molybdenum and molybdenum-base alloys have found

many important applications as a refractory metal utilizing high temperature

) properties, high electrical and thermal conductivity, and corrosion resistance.

In addition to its metallurgical applications, molybdenum is also used in a wide

range of chemical applications, including catalysts, pigments, lubricants, and

corrosion inhibitors, accounting for up to one tenth of total molybdenum demand.

This wide range of technical benefits leads to distribution of molybdenum

usage over a wide variety of intermediate products, as shown in Table 5. The

category of low alloy steels may be further broken down into carburizing steels,

elevated temperature steels, oil country tubular goods, and other wrought steels,

each of thase categories being large enough to stand separately.

P36-2
-3-

An important aspect of this diversity is that most industries with the need of

a substitute for a critical metal have already had experience with molybdenum.

Consequently, suvstitution of molybdenum is most frequently an extension of known

technology without the difficulties of opening completely new technology.

In contemplating an effort to decrease dependence on critical metals, it

should be recalled that during World War II, it was at the direction of the War

Materials Board that the "NE-steels" (National Emergency steels) were developed.

These steels were based upon utilization of molybdenum and the "triple-alloy"

concept to munimize the total use of critical metals. Subsequently, those steels

which were both technically and economically justified were accepted as standard

SAE grades and are still in use today.

PROCESS OF MATERIALS SUBSTITUTION

For over fifty years molybdenum has been the focus of a research and

development effort aimed at identifying potential applications of molybdenum and

bringing them to commercial reality. The growth of molybdenum at a rate exceeding

that of total economic growth over that period is testimony in support of

directed innovation. The four steps of innovation as cited in the keynote presentation

are Foundation, Invention, Demonstration, and Implementation. Utilizing the

foundation of all metallurgical knowledge to which this effort makes its own

contribution, the evolutionary invention of new applications of molybdenum has gone

forward. The laboratory demonstrates that new alloys can meet specified technical

goals, but the real successes of Demonstration are those achieved in partnership

with individual producers of the intermediate product. The production and processing

of a commercial-size trial heat and its subsequent utilization with typical field

practice are the essential elements of Demonstration. Climax Research and

Development then stimulates Implementation through assistance with formal

organizational acceptance and specification, through assistance in development of

P36-3
-4-

field practice, and through screening tests to minimize the risk and cost of

substitution.

All projects carried through this process are economically justified. If

Invention produces an interesting technical concept but one that cannot win the

economic competition of the marketplace, it is recorded and set aside. Demonstration

and Implementation require the cooperation and commitment of an intermediate

product producer. Without economic incentive there is not likely to be any

commercialization. However, it is possible to note instances where the risk

associated with critical metal disruption is high enough that Demonstration of a

new alloy will be carried out even when the substitution is known to be currently

uneconomic. These observations are important, for while economic competition is

an efficient and powerful engine for economically justified innovation, an

alternative incentive or mechanism must be provided for anticipatory development

of currently uneconomic technology.

USE OF MOLYBDENUM AS A SUBSTITUTE FOR CRITICAL METALS

The remainder of this discussion will concentrate on actual substitutions

for critical metals, including those presently in progress, those that could

easily become economic, and those that are technically feasible but unlikely to

be economically justified. Substitution in its broad definition can include

redesign of whole systems, but for the present discussion it will be defined

narrowly to mean identification of an alternative metal meeting all specifications

with only minor accomodations of design. It will be assumed that it is necessary

to deal with only one critical metal at a time, and that the problem is a supply

limitation or an extraordinary price increase, e.g., more than four to tenfold.

The discussion will not seek the complete resolution of the problem of any one

critical metal but rather to indicate the role of molybdenum in partial substitution

for the critical metal.

P36-4
-5-

COBALT

Cobalt is an ideal first example because it has recently experienced a period

of sharply reduced availability and abruptly increased price with an uncertain

price future. The rapid response of users in developing substitutes and reducing

their dependence on cobalt demonstrates the power of the mechanism of economically

justified substitution.

Cobalt is an important element, serving as a base for high temperature creep

resistant alloys, hardfacing and wear resistant alloys, and high temperature spring

and bearing alloys. As an alloy addition, cobalt is used in high speed and tool

steels for hot hardness and temper reisistance, in tungsten carbide tool materials

as a binder, and in alloys with special magnetic , electrical, or mechanical

properties.

The use of cobalt in superalloys can be reduced through a shift toward the

nickel-base alloys. Extensive rebalancing of the alloy composition is necessary

as the strenthening by geometrically close packed phases such as carbides must be

sacrificed. Molybdenum additions for solid solution strengthening and enhanced

y' -strengthening are part of the resolution of the multifaceted problem of

matching strength, creep resistance, oxidation resistance, corrosion resistance,

and fabricability . A new alternative to rebalancing within the conventional

superalloy systems is the new Ni-Mo-Al superalloy. Even with a strong commercial

incentive, the progress of substitution is slow because of the high risk associated

with a failure and the expense of alloy testing and qualification.

Near the opposite extreme is the use of cobalt in hardfacing where competition

is based on performance and cost rather than industry code, and substitutions can

be readily made when a favorable relationship is demonstrated. The surge in cobalt

prices brought research programs in progress for several years to immediate

attention. The result was rapid commercial demonstration and implementation. A

number of cobalt-free alternatives are now commercially available, such as the

P36-5
- 6-

Climax-developed XN930C (Ni-9% Mo-30% Cr-2.0% C) which meets the performance

specifications of the cobalt-base Stellite 6 .

Although combinations of chromium, molybdenum, and tungsten may be used to

produce the critical properties of highly alloyed high speed and tool steels,

cobalt is necessary if the conventionally produced alloys are to be forgeable.

The cobalt supply situation has accelerated development of alternative processing

techniques that avoid the necessity of using cobalt. For example, Crucible Steel

Tl has utilized powder metallurgy techniques to produce CPM Rex 25 (6.5% Mo) and

20 (10.5% Mo) which are cobalt-free alternatives to T-15 (5% Co) and M-42 ( 8 % Co).

MP-35N^ ( 35 % Co) and Elgiloy^ (40% Co) have performed satisfactorily for

springs and down-hole tooling equipment for sour gas wells. When the extremely

several environments of the ultra-deep Mississippi sour gas wells (over 25,000

feet) were encountered, MP-35N was considered as a candidate for casing and tubing.

The radical increase in cobalt price necessitated the qualification of cold worked

nickel-base C-276 (16% Mo) for this application.

Finally, for cobalt, it is possible to cite a cobalt-base alloy highly

resistant to substitution. Although a number of Cr-Mo stainless steels or

nickel-base alloys might reasonably be considered on their techical merit. CobaltT4 based Vitallium which is used for prothesis of human bone is unlikely to change.

With immense liability consequences, demonstration, let alone implementation, is

a step not lightly undertaken.

CHROMIUM

It is difficult to overstate the importance of chromium as an alloy addition

and the economic disruption that would accompany an interruption of chromium supply.

Tl Trademark of Colt Industries, Crucible Steel Divison.

T2

Trademark of E.I. du Pont de Nemours.

T3 Trademark of Elgiloy Company, division of American Gage and Machine Company

T4 Trademark of Howmet Corporation.

P36-6
-7-

Chromium provides hardenability , corrosion resistance, oxidation resistance,

and wear resistance, as well as serving in plating, refractories, and chemical

applications at modest cost to the user. Recent steelmaking advances such as the

argon-oxygen decarburization process, have only encouraged greater reliance on

chromium. Certainly its unique technical contributions necessitate a stockpile

of chromium, in an appropriate form, to meet the strategic needs of the nation.

But the dependence on chromium is so broad economically, that substitutes must be

developed if the nation is to realize political freedom of action.

One application of chromium is easily replaced. At its present price and

availability, chromium is frequently used as a hardenability addition for steels

and irons. Even now through "price book metallurgy" the switch from the Cr-Ni

SAE 9300 (1-1.4% Cr) steels to the Ni-Cr-Mo EX-55 (0.4-0.65% Cr) is economically

justified while providing improved hardenability and toughness. Although not

presently justified economically, a 2Ni-lMo steel has been carried through fullsize commercial demonstration as a competent substitute for EX-55. This demonstration

was undertaken by a tooling company to provide insurance against any future

chromium disruptions. It demonstrates that the hardenability applications of

chromium are strictly a question of economics and that substitution would be

readily achieved.

Substitutions are much more difficult to achieve when it is necessary to

change to a new producing industry and develop new application practice. For

example, Si-Mo nodular cast iron can be considered as an alternative to Cr-Mo

steel in a number of heat resistant applications. However, even in the cases

that are economically justified, the mechanics of transition are almost

unsurmountable without the impetus of real crisis.

P36-7
- 8 -

The definition of a stainless steel is founded on the passive film

characteristic of steels containing in excess of 12 percent chromium. Although

alternative alloy systems may be suggested, none have the utility or ease of

production, fabrication, and application that are associated with the common

stainless steels. Molybdenum is well known to stabilize the passive film

against localized break down, particularly in the presence of chlorides. There

is even a rule of thumb that molybdenum is three times more powerful than

chromium in terms of weight percent in its effect on corrosion resistance.

However, this favorable relationship describes the synergistic relationship of

chromium and molybdenum used in their customary proportions. While use of

additional molybdenum will permit reduction of chromium content, the molyhdenum

addition rapidly becomes disproportionately larger than the chromium reduction

and the total substitution is limited by phase instability. However, one

example of reduced chromium requirement is the alternative of using the austenitic

T5 stainless steel AL-6X (20Cr-6Mo-24Ni) for seawater condenser tubing in place of

T5

the ferritic stainless steel AL 29-4C (29% Cr-4% Mo).

TANTALUM

Tantalum is a metal already so expensive that it is difficult to consider

economic incentives for further substitution. Tantalum is used sparingly to

utilize its extraordinary corrosion resistance in certain chemical environments,

its compatability with human tissue, and its highly stable carbide as a strengthener

of high temperature superalloys. In a few of the corrosion applications of tantalum

molybdenum metal may be considered as a substitute. In conventional superalloys,

the contribution of tantalum to high temperature creep resistance can be replaced

T5 Trademark of Allegheny Ludlum Steel Corporation.

P36-8
-9-

by a combination of Nb, Ti, and Hf carbide strengthening and Mo and W solid

solution strengthening. The development of the new generation of Ni-Mo-Al

superalloys and the application of rapid solidification rate (RSR) technology

offer the potential for reducing dependence on this critical metal in the

future

.

TITANIUM

Titanium and titanium-base alloys are used structurally when a high

strength- to-weight ratio is desirable as in the case of airframes. Titanium

provides excellent corrosion resistance in a wide range of chemical environments,

including seawater. Titanium is employed for its reactivity with carbon and

nitrogen as a stabilizer of stainless steels. In microalloy additions, titanium

has been used for HSLA steels.

Molybdenum is able to offer economically competitive substitutes for

titanium in most of its corrosion applications. For example, there is presently

an active competition of molybdenum-containing stainless steels (29Crr-4Mo,

26Cr-3Mo-2Ni, 20Cr-6Mo-24Ni) with titanium for power plant condenser tubing where

seawater is the coolant. Matching the excellent strength-to-weight ratio of

titanium and its alloys is more difficult. However, alternatives are known,

including a few that use molybdenum such as 13-8Mo (13% Cr-8% Ni-2% Mo-1% Al), a

precipitation hardened stainless steel. In HSLA steel, transformation-controlled

steels containing molybdenum or vanadium may be used as satisfactory substitutes

for the titanium containing steels.

CONCLUSIONS

Molybdenum has been, is, and will remain a domestic material that is readily

available in supply adequate to handle its present and future potential applications.

Molybdenum is a technically versatile element with widely diversified applications

P36-9
- 10-

and years of industrial experience demonstrating its ease of utilization. More

than fifty years of focused research and development have placed molybdenum in

a highly advanced state of economic substitution in all steps of the innovation

process: Foundation, Invention, Demonstration, and Implementation. Associated

with the progress of economic substitution, the status of substitution not presently

economic is also highly advanced, with many alternative metals lacking only

implementation. Molybdenum technology is a powerful and versatile tool for

reducing dependence on critical metals.

P36-10
Table 1

MOLYBDENUM CONSUMPTION BY GEOGRAPHIC AREA*

(Million Lb Molybdenum)

1976 1977 1978 1979 1980**

United States 57 60 69 71 60

Western Europe 70 70 72 75 66

Eastern Bloc 15 17 22 22 18

Japan 25 24 25 25 26

Other 10 11 12 12 12

Total 177 182 200 205 182

Consumption of molybdenum produced in Western World,

**Preliminary estimates.

P36-11
Table 2

WESTERN WORLD MOLYBDENUM PRODUCTION

(Million Lb Molybdenum)

By Geographic Area

1976 1977 1978 1979 1980*

United States 113 123 131 144 151

Canada 31 33 32 22 32

Chile 24 24 28 30 30

Other 3 3 3 4 5

Total 171 183 194 200 218

By Type of Mine

Primary 92 100 106 106 , 123

By-Product 79 83 88 94 95

Total 171 183 194 200 218

*Preliminary estimates.

P36-12
Table 3

SCHEDULED NEW MOLYBDENUM MINES

Est. Annual

Mine Country Company

Estimated

Startup

Production

(Million Lb)

Continental USA Anaconda 1981 7-8

Highmont Canada Teck 1981 6-8

Kitsault* Canada AMAX 1981 9-10

Nevada Maly* USA Anaconda 1982 12-15

Thompson Creek* USA Cyprus Mines 1983 15-21

Goat Hill* USA Molycorp 1983 18-20

*Primary mines.

P36-13
Table 4

MOLYBDENUM PROSPECTS UNDER STUDY

Mine Country

Adanac Canada

Mt. Tolman USA

Bingham Expansion USA

Boss Mountain Expansion* Canada

Mt. Emmons* USA

Quartz Hill* USA

^Primary mines,

**Estimated additional production.

Company

Feasible

Startup

Est, Annual

Production

(Million Lb)

Placer 1983 6

AMAX 1984 19-23

Kennecott 1985 7**

Noranda 1988 8**

AMAX 1989 30

U.S. Borax 1990 26

P36-14
Table 5

MOLYBDENUM CONSUMPTION BY INTERMEDIATE PRODUCTS

(Percent of Total Consumption)

Intermediate Product 1977 1978 1979 1980

Low Alloy Steels 49 47 46 46

Stainless Steels 20 20 20 21

Tool Steels 9 9 10 10

Chemicals & Lubricants 8 9 9 8

Cast Irons & Steels 7 7 7 6

Molybdenum Metal 3 4 5 5

Superalloys 3 3 3 3

Other _1 _1 _0 _L

Total 100 100 100 100

P36-15
NICKEL AS A SUBSTITUTE FOR METALS IN CRITICAL SUPPLY

Robert J. Johnson

International Nickel Co.

P37
NICKEL AS A SUBSTITUTE FOR

METALS I N CRITICAL SUPPLY

R. J, Johnson

Manager, Sales Development

The International Nickel Company, Inc,

One New York Plaza

New York, N, Y, 1000A

Workshop on Conservation and Substitution

Technology for Critical Materials

Vanderbilt University

Nashville, Tennessee

June 15-17, 1981

U.S. Department of Commerce, National

Bureau of Standards and U.S. Department

of Interior, Bureau of Mines

P37-1
Eighty years of research, production and field experience HAVE TAUGHT US MANY THINGS ABOUT NICKEL, INCLUDING THE

TECHNICAL RATIONALE SUPPORTING A YEARLY WORLD CONSUMPTION OF

1.2 BILLION POUNDS. ACCORDINGLY, WE ARE VERY PLEASED TO

CONSIDER WITH YOU SOME TECHNOLOGICAL OPPORTUNITIES FOR

INCREASING THE USE OF NICKEL TO REPLACE OTHER METALS IN

LIMITED SUPPLY. 1 REFER SPECIFICALLY TO CHROMIUM, COBALT

AND TITANIUM. BUT BEFORE WE DISCUSS THESE MATTERS, LET ME

PRESENT TWO BRIEF REMINDERS’.

Slide No. 1 - Worldwide Commercial Sources of Nickel

We are fortunate that nickel occurs naturally on every

CONTINENT. THIS CIRCUMSTANCE FAVORS UNINTERRUPTED SUPPLY

DESPITE RECURRING D OLI T I CAL UPHEAVALS AROUND THE WORLD.

In the longer view, however, we must appreciate that all

METALS FOUND ON SPACESHIP EARTH WILL IN TIME BE IN CRITICAL

SUPPLY, SO OUR CONSUMPTION AND CONSERVATION PRACTICES MUST

CONSTANTLY BE IMPROVED. JUST NOW, THE UNITED STATES AND

ITS NEIGHBORS ARE IN A FAVORABLE SITUATION WITH RESPECT TO

NICKEL AVAILABILITY.

Slide no. 2 - U. S. Primary Nickel Consumption by

End-Use Markets

Nickel has proven to be a hugely versatile element, and

WE ESTIMATE THAT TODAY IT IS USED IN SOME 3000 ALLOYS,

CHEMICAL COMPOUNDS AND PLATING SYSTEMS FOR APPLICATIONS

NUMBERING IN THE TENS OF THOUSANDS, THIS GRAPH SHOWS, BY

P37-2
MARKET SECTOR, WHERE THE U, S, CONSUMED 325 MILLION POUNDS OF

nickel in 1980, Stainless and alloy steel together lead with

43% OF THE MARKET. NEXT IS COPPER AND NICKEL-BASE NONFERROUS

METALS FOLLOWED BY PLATING AND CHEMICALS, THEN FOUNDRY. Let's

EXAMINE SOME CONSERVATION OPPORTUNITIES IN EACH OF THESE

MARKET SECTORS, BEGINNING WITH STAINLESS STEELS. (SLIDE OFF)

Domestic consumption of these remarkable materials has

CLIMBED IN RECENT YEARS TO OVER ONE MILLION TONS ANNUALLY -

1.2 MILLION TONS IN 1980. SEVENTY PERCENT OF THIS IS NICKELCONTAINING. Stainless steels utilized a third of the nickel

AND 70% OF THE CHROMIUM CONSUMED IN THIS COUNTRY LAST YEAR

Indeed, with one exception, applications are so diverse that

NO SINGLE USE ACCOUNTS FOR MORE THAN ABOUT TvvO PERCENT OF

TOTAL SHIPMENTS. THE STRONG POSITION OF THESE STEELS IN OUR

SOCIETY RESIDES IN TWO TECHNICAL FACTORS:

a) Chromium's contribution to chemical passivity

AND CORROSION RESISTANCE,

b) Nickel's effect on the allotropy of chromiumcontaining IRON, RENDERING IT AUSTENITIC AT ROOM

TEMPERATURE AND GREATLY ENHANCING MECHANICAL

( 2 ) PROPERTIES AND FABR I CAB I LI TY

,

Since our task at the moment is to examine the alternate

USE OF NICKEL FOR CHROMIUM, IT IS REASONABLE TO INQUIRE ABOUT

CORROSION RESISTANT NON-CHROMIUM MATERIALS WHICH MIGHT BE

USED IN PLACE OF STAINLESS STEEL, AND WHETHER STAINLESS STEELS

CONTAINING LESS THAN ABOUT 11% CHROMIUM ARE FEASIBLE.

P37-3
Very early in this century, before stainless steels and

AUTOMOBILES ATTAINED COMMERCIAL IMPORTANCE, STEELS CONTAINING

AS MUCH AS 30 1 NICKEL WERE USED FOR THEIR CQPROSION RESISTANCE.

Our archives contain references to such alloys in harness

FITTINGS, BOILER TUBES AND VALVES FOR THE SEA WATER SYSTEM

INSTALLED BY NEW YORK ClTY FOR FIGHTING FIRE.®

Slide No. 3 - Possible Substitutes for Stainless Steels

to Conserve Chromium

Of the commercially available materials nickel silver

(55Cu-18N i -Bal . Zn), with early origins in Chinese coinage,

HAS BEEN POPULAR OVER THE PAST ONE HUNDRED AND FIFTY YEARS

FOR HOLLOWARE, ARCHITECTURAL DETA I LS

^ PLUMB I NG FIXTURES AND

ELECTRONIC COMPONENTS. PERHAPS YOU HAVE NOTED ITS USE IN

SOME OF THE OLDER BANKS, HOTELS AND OFFICE BUILDINGS.

Monel* alloy A09 (30Cu-Bal.Ni ) and its metrications were

INTRODUCED EARLY IN THE 1900 ' S AS NATURAL DERIVATIVES OF

Canadian ores containing both nickel and copper. Monel has

REMAINED A VERY USEFUL ADDITION TO THE FAMILY OF CORROSIONRESISTANT NONFERROUS ALLOYS SERVING THE CHEMICAL AND PROCESS

INDUSTRIES

.

About 1930, the cupronickels (70Cu-3QNi and 90Cu-10N i

)

MADE THEIR APPEARANCE. THEY NOW FIND MANY APPLICATIONS IN

POWER PLANTS AND THE MARINE INDUSTRY WHERE AGGRESSIVE WATERS

AND BO I FOUL I NG ARE ENCOUNTERED.

"Trademark The International Nickel Company, Inc.

P37-4
In numerous situations, substitution of these nonferrous

ALLOYS FOR STAINLESS STEELS COULD BE MADE WITH NO PENALTY

except cost, Other alloy changes, especially in the chemical

INDUSTRY, WOULD REQUIRE MODIFICATION OF PROCESS STREAMS TO

MINIMIZE CORROSION,

Of course, a serious shortage of chromium would greatly

STIMULATE THE USE OF ALUMINUM, PLASTICS AND MANY KINDS OF

COATINGS AS SUBSTITUTES FOR STAINLESS STEELS. (SLIDE OFF)

.

Recent Inco work for the Bureau of Mines suggests that

IT MAY BE POSSIBLE TO DEVELOP "STAINLESS'" STEELS CONTAINING

ONLY 9 1 CHROMIUM REINFORCED BY ADDITIONS OF NICKEL AND

MOLYBDENUM - AND PERHAPS COPPER AND VANADIUM - FOR MILDLY

ill)

CORROSIVE SERVICE, MUCH REMAINS TO BE DONE ON THIS LINE.

Current research to learn more about the effect of

NICKEL ON PITTING AND REPASSIVATION MAY LEAD TO A BETTER

UNDERSTANDING OF AQUEOUS CORROSION AND POSSIBLV TO LOWER

CHROMIUM MODIFICATIONS, UNFORTUNATELY, IT APPEARS THAT THESE

ATTEMPTS TO REDUCE CHROMIUM MAY ENTAIL INCREASES IN OTHER

ALLOYING ELEMENTS, MAKING THE RESULTANT NEW COMPOSITIONS

MORE EXPENSIVE.

We do see some promise in studies dealing with austenitic

STEELS FOR HIGH TEMPERATURE APPLICATIONS IN FURNACES AND

VEHICULAR EMISSION CONTROL DEVICES, THIS WORK SUGGESTS THAT

SOME CHROMIUM MAY BE SAVED BY ADDITIONS OF SILICON AND

( 5 ) ALUMINUM, ALONE OR IN COMB I NAT ION.

P37-5
Please permit me to restate the fact that chromium

IS UNEQUALLED IN ITS ABILITY TO FORM THE ADHERENT, IMPERVIOUS

OXIDE FILMS WHICH PROTECT STAINLESS STEELS FROM AQUEOUS AND

HIGH TEMPERATURE ATTACK. MOREOVER, FIFTY YEARS OF RESEARCH

HAVE FAILED TO PROVIDE A REPLACEMENT FOR CHROMIUM IN THIS

PARTICULAR ROLE. It SEEMS UNLIKELY, THEREFORE, THAT THIS

AUDIENCE WILL SEE COST-EFFECTIVE, METALLIC ALTERNATES FOR

THE ESTABLISHED HIGH TONNAGE STAINLESS STEELS.

We should turn now to alloy steels , an eight million

TON MARKET WHICH CONSUMED 40, 000 TONS OF CHROMIUM IN 1980.

We saw earlier that 10% of the annual U.S. nickel requirement

GOES INTO ALLOY STEEL, MAINLY FOR IMPROVED STRENGTH AND TOUGHNESS. AS A HARDENER, NICKEL ALONE IS NOT A STRONG PERFORMER

J

IT DOES BETTER IN COMBINATION WITH SMALL QUANTITIES OF OTHER

ALLOYING ELEMENTS SUCH AS CHROMIUM, MOLYBDENUM AND MANGANESE.

Because the theoretical aspects of hardenabi lity and alloy

ELEMENT INTERCHANGE ARE WELL KNOWN, 1 WILL ONLY NOTE THAT

LOW NICKEL ALLOY STEELS HAVE A LONG HISTORY BEGINNING WITH

THE USE OF 3l AND 51 NICKEL STEELS FOR ARMOR PLATE AND

BICYCLE CHAINS BEFORE THE TURN OF THE CENTURY.^ SUCCESSFUL

EXPERIENCE WAS THEN TRANSFERRED TO CHAIN DRIVES AND OTHER

COMPONENTS FOR CARS AND TRUCKS, AND TODAY NICKEL-MOLYBDENUM

AND NICKEL-CHROMIUM-MOLYBDENUM ALLOY STEELS ARE CALLED UPON

FOR THE MOST DEMANDING SERVICE IN ALL KINDS OF MACHINERY.

The point to be made here is that a very large tonnage of

CHROMIUM COULD BE SAVED, AT A MARKED COST PREMIUM, BY

SUBSTITUTIONS WITH NICKEL. ALL THE REQUISITE TECHNOLOGY

IS IN PLACE, AND WE HAVE WARTIME EMERGENCY EXPERIENCE TO DRAW UPON.

P37-6
Slide No. A - Effect of Nickel on the Cleavage

Strength of Iron

The explanation for the longstanding preference for

NICKEL ALLOY MACHINERY STEELS RESTS IN THE UNIQUE ABILITY

OF NICKEL TO RETARD CRACK INITIATION AND PROPAGATION IN

FERROUS MATERIALS. THIS WORK BY FlOREEN AT OUR LABORATORY

in Sterling Forest, New York shows the well-known drop in

FRACTURE TOUGHNESS WHICH IRON EXHIBITS AS TEST TEMPERATURE

DECREASES. THE BENEFICIAL EFFECT OF 0.3 TO 3.91 NICKEL n N

CLEAVAGE STRESS AT ALL TEMPERATURES IS QUITE APPARENT , ' (SLIDE Of

Another opportunity to conserve chromium involves the

HIGH STRENGTH STRUCTURAL STEELS. THROUGH A COMPLEX MECHANISM

AFFECTING OXIDATION BEHAVIOR, NICKEL PERMITS ADDITIONS OF

COPPER TO STEEL WHICH WOULD OTHERWISE BE PROHIBITIVE BECAUSE

OF THE LATTER'S CONSTRAINTS ON HOT WORKABILITY.^ THIS

TECHNOLOGY OPENS THE WAY TO GREATER USE OF COPPER IN PLACE

OF CHROMIUM FOR STRENGTH AND CORROSION RESISTANCE AS IN

certain ASTM A2A2 steels or the Inco developed N i -Cu-Cb steel

of ASTM A710.

Outside the 9N i -4Co steels and the maraging steels

(18N

I

-8Co-5Mo) , WHICH FEATURE very high strength, cobalt

IS NOT ENCOUNTERED IN COMMERCIAL ALLOY GRADES. .M.ARAGING

STEEL USAGE HAS BEEN CURTAILED LATELY BY THE HIGH PRICE

OF COBALT, AND A VERSION OF THE 18N I -250 ALLOY CONTAINING

NO COBALT AND LESS MOLYBDENUM IS BEING DEVELOPED BY INCO,

P37-7
Titanium shipments amounted to 54 million pounds last

YEAR., THE MAJOR END-USES BEING AIRCRAFT GAS TUPBINES (40%),

AIR FRAME COMPONENTS (35%), AND CORROSION RESISTING EQUIPMENT

FOR THE POWER, CHEMICAL AND PAPER INDUSTRIES (25%)

Titanium offers a favorable combination of strength, weight,

TOUGHNESS, MODULUS OF ELASTICITY AND RESISTANCE TO CORROSION

FOR USE IN JET ENGINES, NICKEL STEELS SUCH AS ANS 6415

(1 . BIN i , 0,8 Cr, 0,25No) could be used in critical rotating

DISC APPLICATIONS, AND AlvlS 5bl6 (13CR, 2Nl, 3W) FOR BLADES,

These steels were specified for such applications before

TITANIUM WAS ACCEPTED, BUT BOTH REQUIRE CHROMIUM,

Similar conservation difficulties are presented in the

USE OF LIGHT-WEIGHT ULTRA HIGH STRENGTH STEELS AS ALTERNATES

TO TITANIUM IN AIR FRAME STRUCTURES, ALL THE COMMERCIAL

HIGH STRENGTH NICKEL ALLOYS SUCH AS 300-F1, 9Ml-4Co STEEL

AND THE MARAGING STEELS CONTAIN CHROMIUM OR COBALT.

High nickel alloys such as Inconel* alloy 625 (2iCr9NO-BAL. INI ) and Hastelloy+ 0276 (15Cr-16.m

< o- 3 . 75*7-

2 . 5Co-56N I ) COULD REPLACE titanium in various chemical

PROCESS OPERATIONS, BUT YOU WILL PERCEIVE THAT THIS WOULD

INCREASE REQUIREMENTS FOR OTHER CRITICAL MATERIALS, HENCE,

THERE SEEMS TO BE NO ALLOY FREEWAY IN CERTAIN AREAS OF OUR

TECHNOLOGY,

Moving over to nonferrous materials for elevated

TEMPERATURE SERVICE, WE OBSERVE THAT WHEN EXPOSED TO

"Trademark The International Nickel Company, Inc,

+Trademark Cabot Corporation

P37-8
AIR AT Hl r-U TEMPERATURES, NICKEL IS MUCH MORE RES I STANT

TO OXIDATION THAN IRON, THE LATTER FORMS THICK

OXIDE SCALES WHICH TEND TO CRACK AND FALL AWAY, EXPOSING THE

METAL UNDERNEATH TO FURTHER ATTACK, By COMPARISON, NICKEL

TENDS TO FORM THIN, TENACEOUS SCALES WHICH PROTECT UNDERLYING

strata, Additions of chromium and aluminum greatly augment

THIS BEHAVIOR BY ENTERING THE FORMATION OF CHM D LEX SURFACE

OXIDES WHICH ARE EVEN MORE PROTECTIVE, ADDITIONALLY, NICKEL

IS AN EXCELLENT RECEPTOR FOR ELEMENTS WHICH ADD STRENGTH

BY SOLID-SOLUTION HARDENING OR THE CONTROLLED FORMATION AND

DISTRIBUTION OF I NTERMETALLI C COMPOUNDS, LASTLY, NICKEL DOES

NOT COMBINE WITH CARBON THUS RELIEVING METALLURGISTS OF CERTAIN

CONCERNS OVER CARBIDES OR PERFORMANCE IN PROCESS STREAMS RICH

IN HYDROCARBONS, THESE CHARACTERISTICS HAVE BEEN COMBINED

IN A FAMILY OF HIGH NICKEL ALLOYS WHICH FIND MANY IMPORTANT

USES IN THE CHEMICAL PROCESS AND AEROSPACE INDUSTRIES,

One of our publications provides data on some 95 wrought

( 0 ) AND CAST ALLOYS FOR HIGH TEMPERATURE SERVICE, lN REVIEWING

THIS INFORMATION FOR CONSERVATION OPPORTUNITIES, I PREPARED

THE FOLLOWING LIST OF CONSTITUENT ELEMENTS;

Slide No, 5 - Constituents of High Temperature Alloys

This table is informative as to superalloy design.

Nearly all of these alloys contain chromium, usually in the

RANGE OF 15 TO 20%, AND WE DO NOT SEE MUCH OPPORTUNITY FOR

changing this. For reasons already noted, it is technically

P37-9
IMPOSSIBLE TO ACHIEVE PERFORMANCE TARGETS, AT LEAST FOR

AIRCRAFT ENGINES, WITHOUT CHROMIUM. A SMALL REDUCTION IN

THE LEVEL OF CHROMIUM IN SOME ALLOYS APPEARS POSSIBLE, BUT

THIS WOULD REQUIRE A REBALANCING OF COMPOSITIONS AND

SUBSEQUENT TESTING AND REQUALIFICATION FOR INDUSTRY. We

SEE THIS AS A FORMIDABLE TASK IN TERMS OF TIME AND MONEY.

Such work has become incredibly costly, to the point where

ALLOY PRODUCERS AND USERS ALONE CANNOT AFFORD IT. HENCE,

GOVERNMENT FUNDS SUPPORT MUCH ALLOY DEVELOPMENT EFFORT.

The time required to commercialize a new superalloy is in

THE ORDER OF FIVE TO TEN YEARS, AND IF WE COUPLE ALL THIS

WITH NATIONAL PRIORITIES FOR AIR DEFENSE AND ESSENTIAL AIR

TRAVEL, I THINK WE CAN SAFELY CONCLUDE THAT THIS FIELD DOES

NOT OFFER MUCH PROMISE FOR THE CONSERVATION OF CHROMIUM.

(Slide Off)

The substitution of nickel for elements besides chromium

IN HIGH TEMPERATURE ALLOYS HAS BEEN REVIEWED IN EARLIER

(ID)

SESSIONS OF THIS CONFERENCE AND AT OTHER CONFERENCES,

v '

Therefore, we will not spend much time in this area except

TO RECORD THAT THERE APPEARS TO BE SOME PROGRESS IN REPLACEING COBALT WITH NICKEL. A NEW APPROACH TO MORE EFFICIENT

ALLOY UTILIZATION IS iNCO's WORK ON MECHANICAL ALLOYING BY

HIGH ENERGY MILLING. THIS TECHNIQUE PERMITS THE COMPOUNDING

OF ALLOYS WHICH WOULD BE DIFFICULT OR IMPOSSIBLE TO PRODUCE

BY CONVENTIONAL MANUFACTURING ROUTES. HERE ARE THE

CHEMICAL COMPOSITIONS OF TWO NEW PRODUCTS, MADE BY MECHANICAL

ALLOYING, FOR GAS TURBINE VANES AND BLADES.

P37-10
Slide No. 6 - New Gas Turbine Materials Produced by

Mechanical Alloying

I THINK THE IMPORTANT FACTOR HERE IS THAT SUPERIOR PERFORMANCE

CAN RESULT IN AN OVERALL CONSERVATION OF MATER I ALS, NOT

JUST THE ELMI NIATION OF COBALT. ($LIDE ^ FF )

Plating is the next market sector for attention in this

REPORT. You KNOW THAT CHROMIUM IS USED FOR DURABLE, BRIGHT

FINISHES ON COUNTLESS ITEMS, ESPECIALLY HOUSEWARES AND AUTOMOTIVE COMPONENTS. TYPICAL PLATING SYSTEMS FOR DECORATIVE

SURFACES INCLUDE BRIGHT NICKEL DEPOSITS UP TO 1.5 MILS DEEP

COVERED WITH 10 TO 15 MICROINCHES OF CHROMIUM, PRIMARILY FOR

CORROSION RESISTANCE. SOME MACHINERY APPLICATIONS, SUCH

AS HYDRAULIC PISTONS, UTILIZE THICK, HARD CHROMIUM COATINGS

FOR WEAR RESISTANCE, In ALL, THE ANNUAL U.S. CONSUMPTION OF

CHROMIUM FOR PLATING OTHER METALS IS ABOUT 15,000 TONS,

AS WE THINK ABOUT CHROMIUM CONSERVATION, IT IS INTERESTING

TO RECALL THAT NICKEL PLATING WAS WIDELY USED LONG BEFORE

CHROME FINISHES BECAME POPULAR, In FACT, THE PROCESS WAS

PATENTED BACK IN 1840, AND BY THE TURN OF THE CENTURY NICKEL

PLATING HAD BECOME A SYMBOL OF QUALITY. It BECAME THE HABIT

TO CALL ANY ARTICLE OR PROJECT OF COMMENDABLE CHARACTER

"nickel plated", Thus, the New York, Chicago and St, Louis

Railroad, because of its high-grade engineering and strong

n?

)

FINANCIAL BACKING, GAINED THE NAME OF THE "NlCKEL PLATE ROAD" , ~

If chromium for plating were to be restricted, such an

EVENT COULD NOW BE MET WITH BRIGHT NICKEL SURFACES PROTECTED

P37-11
BY VARIOUS TRANSPARENT ORGANIC COATINGS. ADDITIONALLY,

HARD NICKEL PLATING PROCESSES, INCLUDING THOSE FEATURING

THE USE OF ABRASION RESISTING DISPERSOIDS HAVE BEEN

DEVELOPED FOR THE PROTECTION OF MACHINERY PARTS.

Many of the materials we have discussed are also available AS CASTINGS. CONSERVATION OF CHROMIUM IN THE CAST HEAT

AND CORROSION RESISTANT STAINLESS ALLOYS IS POSSIBLE THROUGH

THE USE OF THE Ni-ReSIST* FAMILY OF CAST IRONS (AST!7! A439 AND

A436) WHICH RELY HEAVILY ON NICKEL, COPPER SILICON,

MOLYBDENUM AND, IN SOME INSTANCES LOW PERCENTAGES OF CHROMIUM

/ 17 \

TO OBTAIN DESIRED PROPERTIES.

;

The automotive industry is avidly seeking economy in

MANUFACTURING, AND THIS HAS CREATED NEW INTEREST IN NICKELMOLYBDENUM CAST IRONS TO REPLACE WROUGHT STEELS IN DIESEL

CRANKSHAFTS AND IN CERTAIN GEARS. THESE EVALUATIONS COULD

EVENTUALLY EFFECT SOME SAVING IN CHROMIUM.

Lastly, we know that several prominent producers and

USERS OF CAST PERMANENT MAGNETS ARE CONDUCTING RESEARCH ON

LOWER COBALT ALLOYS FOR USE IN ELECTRICAL MOTORS AND TELECOMMUNICATIONS .

"Trademark The International Nickel Company, Inc.

P37-12
To SUMMARIZE, WE HAVE BEEN CONSIDERING TECHNOLOGICAL

OPPORTUNITIES TO REPLACE CHROMIUM, COBALT AND TITANIUM WITH

NICKEL, ASSUMING PLENTIFUL SUPPLIES OF NICKEL AND POSSIBLE

SHORTAGES OF THE OTHER THREE METALS, OUR ANALYSIS INDICATES

THAT IT WOULD BE POSSIBLE TECHNICALLY TO SUBSTITUTE NICKELCONTAINING MATERIALS SUCH AS MONEL FOR A SUBSTANTIAL TONNAGE

OF STAINLESS STEEL. SIMILARLY, MUCH OF THE CHROMIUM IN

ALLOY STEELS COULD BE REPLACED BY NICKEL, PERHAPS AUGMENTED

BY INCREASED MANGANESE OF* MOLYBDENUM, I'loST OF THE CHROMIUM

FOR PLATING OTHER METALS COULD ALSO BE SAVED THROUGH THE USE

OF ALTERNATIVE NICKEL PLATING SYSTEMS,

AS TO COBALT, THE ONLY LARGE POTENTIAL FOR CONSERVATION

INVOLVES SUPERALLOYS, WHERE DEVELOPMENTS ARE ALREADY TARGETED

ON COBALT REDUCTIONS UTILIZING NICKEL AS THE ALTERNATE ALLOYING

ELEMENT, NEW MECHANICALLY ALLOYED MATERIALS FEATURING OUTSTANDING RESISTANCE TO DETERIORATION IN VARIOUS HIGH TEMPERATURE

ENVIRONMENTS ALSO OFFER OPPORTUNITIES TO CONSERVE SEVERAL

CRITICAL METALS IN GAS TURBINE COMPONENTS.

Some titanium now employed for various aerospace, paper

MILL AND CHEMICAL PLANT APPLICATIONS COULD BE SAVED THROUGH

SUBSTITUTION WITH HIGH STRENGTH STEELS CONTAINING NICKEL AND

WITH HIGH NICKEL CORROSION RESISTING ALLOYS. UNFORTUNATELY,

THESE ALTERNATE MATERIALS REQUIRE CHROMIUM OR COBALT,

This concludes my presentation.

Thank you,

P37-13
References

Q) Chromium in December 1981), Mineral Industry Surveys,

U . S . Department of the Interior, Bureau of Mines,

(2) Fifty Years of Stainless Steel, H, Krainer, Stahl and

Eisen, 82, Oct, 25, 1962, 1527-1540 . British Iron and

Steel Institute Translation No, 3081

(3) A History of Nickel Steels, R.B.G, Yeo and 0,0, Miller,

Sorby Centennial Symposium on the History of Metallurgy,

A i ME 1965, Gordon and Breach Science Publishers,

New York, International Nickel A-408, 1966,

(A) Chromium Substitution in Stainless Steels, S. Floreen,

Contract No, J0295070, U

,

S . Dept, of Interior, Bureau

of Mines, November 1980,

(5) Low Chromium Oxidation Resistant Austenitic Stainless

Steel, u.S. Patent No, A, 102,225, H, T, Michels,

July 25, 1978, The International Nickel Company, Inc,

(6) Cleavage Initiation in Fe-Ni Alloys, f loreen. Met.

Trans,, Vol. 2, May 1971, 1AQ3.

(7) The Effect of Nickel on the High Temperature Oxidation

Characteristics of Copper-Bearing Steels, G,L, Fisher,

Jnl, Iron and Steel Institute, Vol. 207, July 1969,

(8) Titanium 1980, W. W, Minkler, Journal of Metals,

April 1981, Al-AA,

P37-14
(y) High Temperature High Strength Nickel Base Alloys,

International Nickel A-393, 1977

QO; Superalloys 1980, J. K, Tien, et al, American Society

for Hetals, Proceedings Fourth International Symposium

on Superalloys, Sept. 21-25, 1980.

(11) High Temperature Oxide Dispersion Strengthened Alloys,

J. H. Weber, Science of Advanced Materials and Processes

Engineering, Vol. 25, 1980, 752-76A

(12) Automotive Industry of America, Prestige Publications,

Inc., Southfield, Michigan, 1979, 189-193

(13) Engineering Properties and Applications of the N

i -Res i sts

and Ductile Ni-Resists, International nickel A-1231, 1975

P37-15
COMMERCIAL NICKEL SOURCES

P37-16
U.S.A. PRIMARY NICKEL CONSUMPTION

BY END-USE MARKETS

Total 1980 Shipments - 325 Million Pounds.

P37-17
POSSIBLE SUBSTITUTES FOR STAINLESS

STEELS TO CONSERVE CHROMIUM

Nickel Silver (55 Copper-18 Nickel-Bal. Zinc)

Monel (30 Copper-Bal. Nickel)

Cupronickel (90 Copper-10 Nickel)

Aluminum

Plastics

Coatings

P37-18
EFFECT OF NICKEL ON THE CLEAVAGE STRENGTH

OF IRON

Temperature, °C

P37-19
CONSTITUENTS OF HIGH TEMPERATURE ALLOYS

Element

Occurrence - Number of Alloys

Cr 91

Al 79

Ti 72

Mo 63

B 60

Co 55

Zr 45

W 37

Cb 29

Ta 17

P37-20
NEW GAS TURBINE MATERIALS PRODUCED

BY MECHANICAL ALLOYING

MA754 MA6000E

Ni Bal Bal

Cr 20.0 15.0

Mo — 2.0

Al 0.3 4.5

Ti 0.5 2.5

Ta — 2.0

W — 4.0

Zr — .15

B — .01

C .05 .05

Y2O3 0.6 1.1

P37-21
TUNGSTEN - A NEWLY NONCRITICAL METAL

C. C. Tunnsten

AMAX Tungsten

P38
- 1 -

TUNGSTEN - A NEWLY NON-CRITICAL METAL

C. C. Clark*

Tungsten has had a long history as a critical material; one

intimately related to military necessities such as cutting tools,

armor piercing projectiles and high-temperature alloys. In view

of this historical usage association and a common misconception

in this country that most of our tungsten comes from Eastern Bloc

countries, it may come as a surprise to some of you to find that

tungsten is included as a "safe" element to be used as a replacement of critical elements. I would like, therefore, to take a few minutes to bring you up-to-date on the current and future

tungsten supply situation.

TUNGSTEN SUPPLY

Any analysis of the tungsten industry must consider the impact

of the U.S. stockpile on prices, and new mine development. In

1950-51 during the Korean War the General Services Administration

increased its tungsten stockpile goal to 146 million pounds^, Figure

1. Prices became so attractive that by 1955 more than 700 tungsten

mines were operating in the United States. They produced almost 16

million pounds. Actual stockpile purchases far exceeded the 146

million pound objective and reached 210 million pounds before the

program ended in 1957. To place that in perspective, consider that

the 210 million pounds could have supplied the whole Western World

for six years at the 1957 level of consumption.

The stockpile objective was revised downward several times

and by 1958 had reached 50 million pounds leaving a 160 million

pound excess which could have supplied all of the U.S. needs between

1959 and 1971. As a consequence the number of U.S. producers fell

to two and by 1962 the price had fallen to 50C/lb. , Figure 2, when

the GSA began its tungsten disposal program.

The ups and downs of the disposal program had its influence

on prices. The impact of 16.2 and 28.7 million pound releases in

1969 and 1970, respectively, which drove prices from $5. 05/lb. in

1970 to about $2. 00/lb. in 1972 , have been well documented^' 2.

Currently, the stockpile contains a little over 90 million pounds

which is only about 33 million pounds over the 59.1 million pound

objective. We do not feel that this is a fail-safe situation but

’'Manager, Market Development, AMAX Tungsten, P. O. Box 1568 , Ann

Arbor, MI 48106 (313-761-2300). Presented at the DOC-ASM Workshop

on Conservation and Substitution for Critical Materials, Vanderbilt

University. Nashville, TN - June 15-17, 1981.

P38-1
!t

- 2 -

it is a manageable level if the sealed bid-maximum quantity sales

system now in effect is diligently carried out. Releases from the

GSA stockpile have been 4 to 6 million pounds per year for the last

several years.

Now the industry is beginning to feel confident and is making

long range plans with some assurance. New mines have been brought

into production or expanded since 1975, Table I, and more are

scheduled in the near future, Table II. The largest of these is

AMAX ' s huge MacTung deposit near the MacMillan Pass on the YukonNorthwest Territories border. This scheelite deposit is estimated

to contain 63 million tons of ore averaging 0.95% WO3 . This corresponds to 431,000 metric tons of tungsten. To place that in perspective with other deposits, consider the fact that the Peoples'

Republic of China is estimated^ to have "known and probable tungsten

reserves" of 952,600 metric tons, Table III. Thus, this one deposit

contains the equivalent of 40% of the estimated Chinese tungsten

deposits. It should be noted, however, that the MacTung deposit

was discovered in 1962 but its development could not be justified

because of the large quantity of excess tungsten overhanging the

marketplace in the GSA stockpile. The decision to proceed with

the development of MacTung is expected sometime in 1981. Its initial

production at the rate of about 7 million pounds per year will

substantially increase the supply of tungsten from stable areas,

Figure 3.

Our estimate of the tungsten supply-demand for the Western

World is shown in Figure 4. What is of perhaps even greater

importance is that North America is expected to become self-sufficient

in tungsten before the end of this decade, Figure 5.

There is a misconception in this country that China and North

Korea are large suppliers of tungsten to the Western World. It is

not possible to get accurate figures on this because statistics are

sparse and the trade flow is complex. Our observation is that

these countries have not been able to satisfy Eastern Bloc needs

in recent years and that there has been a net flow from the West

to the East for most of the past ten years.

The impact of the GSA tungsten stockpile on the tungsten

industry is not an isolated case. Other metals, especially those

critical materials which we are talking about replacing, were

released in quantity during the 1970's. In many instances shortages soon developed 4 because the mining industry simply could not

justify bringing new mines into operation as long as the GSA was

acting as a "major mine". Another way of saying this is that

artifical markets which exist when normal commercial materials'

economics are disregarded make it difficult, if not impossible,

for an industry to develop in an orderly fashion.

Now this country's metallurgical and scientific community is

embarking on a program to implement the recently enacted National

P38-2
-3-

Materials Minerals, and Research and Development Act of 1980

(PL96-479) . We will undoubtedly become engaged in federally

funded programs and I hope that established materials economics,

normal commercial business practices, and just plain common sense

will not be ignored. The tungsten industry has felt the effects

when these factors were ignored and I for one am concerned about

the wisdom of embarking on an R & D program such as we are discussing at this meeting.

TUNGSTEN APPLICATIONS

Rather than speculate on ways that tungsten or tungsten containing alloys might substitute for the critical elements and their

alloys, I am going to touch upon some of the benefits tungsten

imparts to various alloy systems. Some examples will be discussed.

I think that this is the way that I can be most helpful to you in

your efforts to consider viable alternate alloys with lower critical

element content.

CEMENTED CARBIDES

Approximately 65% of the tungsten consumed in the U.S. is

used in cemented carbides. Tungsten carbide has formed the backbone of the carbide industry for many years because it provides

the combination of hardness, transverse rupture strength and

toughness necessary for many tough wear applications in the oil

drilling, mining and many industrial wear applications. These

applications utilize grades which contain 8-30% cobalt which some

of you may consider a logical target for substitution, despite the

fact that less than 10% of the cobalt is used in cemented carbides.

Much effort has been devoted to this over the years but so far no

binder has been found which does not impair properties. Furthermore, the high cobalt and tantalum values have spurred development of processes to recycle carbides. Currently, the industry

is recycling a high proportion of the scrap carbides so that little

cobalt is actually being consumed. More about that later.

Let's not forget that productivity is an all important consideration in a business/political climate which leads to materials

shortages. In fact, as we all know the U.S. seriously lags other

countries in productivity even in today's sluggish economy. The

use of coated tungsten carbides has grown rapidly in the last few

years and has significantly improved machine productivity by increasing machining speeds5. Figure 6. The use of coated tools could

reach 80% in several years especially as old slower machines are

replaced

.

These coatings consist of 5-15y thick layers of alumina,

TiC, TiN, or other very hard but brittle ceramic type materials.

To be sure, they do not permit operation in the speed ranges of the

P38-3
-4-

cements and ceramics but they significantly extend the speed

range of uncoated WC. Most machine tools operating today cannot

achieve speeds and the rigidity required to take advantage of

the cermets.

Since coatings are brittle, care must be taken to be sure

that the substrate provides the required properties^. High deforma

tion resistance is necessary to prevent flaking of the coating and

to maintain the original cutting edge geometry. At the same time,

high toughness is necessary to maintain resistance to crack initiation and propagation. Cemented tungsten carbides can be tailored

to provide optimum substrate properties often through addition of

other carbides.

Since cemented tungsten carbide is so essential to high produc

tivity, it is important that the critical elements such as cobalt

and tantalum used in concert with the WC be recovered. Several

processes have been developed, Figure 7, which are capable of

recycling carbide compacts. In some, such as the zinc process,

these elements remain in situ and the product of the process is

a ready-to-press powder which I understand is suitable for most

cemented carbide applications. The zinc process is reported to

be very energy efficient utilizing only 3.6 kw hr. /kg. The process

is very efficient as metallic recoveries are on the order of 99.9%.

Process efficiency is only one side of any recycling effort.

Currently, recycled material represents about 25% of the cemented

carbide produced today^ . This percentage is expected to increase

in the future but the actual volume recycled will depend upon price

and scrap availability. Since this meeting is concerned with

material shortages, I have talked with several persons who are

knowledgeable about the carbide scrap industry to get an idea of

how much could be recycled in the event of a critical shortage of

cobalt or tantalum and how much is being recycled today. These

conversations are summarized in Table 4. A much higher percentage

of the tungsten carbide consumption is available for recycling

than the estimated 25% being recycled today. This combined with

the high efficiency of the recycling processes makes it hard to

justify any R & D effort to substitute for cobalt in carbides which

are so crucial to high productivity.

HARDFACING MATERIALS

Tungsten has been used in cobalt base hard facing alloys since

Elwood Haynes developed several in the early 1900's for valve

overlays and other wear parts in his automobiles. The combination

of excellent wear properties and unusually low coefficient of

friction make one alloy, widely known as alloy No. 6, unique for

many critical applications. A number of nickel and iron base

hardfacing alloys are on the market which rely upon either WC or

P38-4
-5-

W2 C particles to provide high wear resistance. These could be

substituted for the cobalt base alloys. Tungsten carbide is ideal

for this type of application because it reforms after passing

through the electric arc.

Often it is not necessary to significantly alter a material

to eliminate a critical element. One example is a change made by

a diesel engine manufacturer in a valve seat inert, which had been

cast in Eatonite for years^. Elimination of the 10% cobalt had

little significant effect on its properties. Table 5. Old files

were checked to find out why cobalt had been added in the first

place. It turned out that the alloy was developed as a hard facing

material and the cobalt was added to stabilize the arc. It just

wasn't needed in the casting.

HIGH SPEED STEELS

Ever since the development of an 8% tungsten tool steel in

1868, tungsten has been an important alloying addition in tool

and high speed steels. Changing mineral economics have resulted

in substitution for tungsten by molybdenum, vanadium and chromium.

For those applications which require high hardness at high temperatures, commonly referred to as red hardness, it was often necessary

to add cobalt along with the tungsten substitutes. Now the trend

has reversed itself and it is cost effective to substitute tungsten

for the cobalt.

W. T. Haswell's presentation earlier in these meetings on the

development of CPM Rex 20 and 25 is an example of how tungstenmolybdenum grades with higher tungsten equivalents can be substituted for the cobalt containing grades. The techniques used in

developing these alloys can be utilized to develop other cobaltfree grades if the market warrants.

SUPERALLOYS

Tungsten's role as a carbide former and strengthener in cobalt

base superalloys is well known. Because of the ready availability

of molybdenum, tungsten's potent contribution to nickel base alloys

was largely overlooked in this country until the Martin Metals

series and the hot corrosion resistant alloys were developed in the

]960's. Russian alloys have always utilized more tungsten.

Actually tungsten contributes many beneficial character istics

to nickel base alloys:

- Potent solid solution strengthener, especially at

highest temperatures and longest times.

- Solid solution strengthens y '

.

P38-5
- Carbide stabilizer - MC type.

- Raises melting point.

- Reduces thermal expansion.

- Reduces diffusivity of Ti and Cr at high temperatures.

- Probably raises y ' solvus temperature.

- Retards transformation of y' to n

.

Tungsten's most potent contribution is as a solid solution

strengthener and carbide stabilizer. In fact, it contributes to

long time microstructural and dimensional stability in many different

ways and its effect seems to persist to the highest temperatures.

An example is the Japanese^ development of an alloy for use in high

temperature gas cooled reactors. Its long time rupture strengths

are compared in Figure 8 with those of cobalt containing alloy 617

which is receiving a lot of attention in this country for similar

applications. These data support the position that tungsten is a potent strengthener at high temperatures and long times; even more

so than molybdenum on an atomic percent basis. However, the density

of tungsten is appreciably higher.

Alloys such as the Japanese HTGR alloy can help this nation

utilize its fuel resources more efficiently. Boilers, reactors,

etc., are designed for very long time service and require materials

which will maintain their properties for the life of the unit.

One example is IN-102 with 3% each of tungsten, molybdenum and

columbium which was developed specifically for superheater tubing

in fossil-fired power plants operating with 1200F steam. Perhaps

someone should look at a rebalanced columbium-free version of this

alloy for possible application in high temperature steam plants.

The alloy not only provides much higher strength than 18-8 type

stainless steels so that thinner wall tubes can be used but it

has only 15% chromium. Use of such an alloy could result in

substantial chromium savings. Test lengths have been operating

satisfactorily in a Public Service boiler for well over 10 years.

HIGH TEMPERATURE STEELS

Tungsten imparts the same beneficial characteristics to elevated temperature steels that molybdenum does on roughly an

equivalent percent basis:

- Tungsten imparts resistance to hydrogen attack.

- Tungsten imparts resistance to temper embrittlement.

- Tungsten increases elevated temperature strength.

Tungsten stabilizes carbides.
-7-

In fact, it may be a sufficiently potent carbide stabilizer

that it might prevent graphitization . This is one application

wherein tungsten might substitute directly for chromium in the

low Cr-Mo steels.

There are data which show that, as in superalloys, tungsten

is most effective as a strengthener at long times and at the

highest temperatures. One important example of this is HT-9,

a Super 12% chromium stainless steel, which has been widely used

in Europe and is receiving consideration in this country for

various elevated temperature applications. Sandvik^O has found

a consistent 10-15% higher rupture strength in HT9 with 0.5%

tungsten than the identical, but tungsten free, HT91. The advantages of HT9 are:

- Excellent operating experience in Europe for over 20

years

.

- Significantly improved strength over standard 9Cr-lMo.

- Data base available for establishment of ASME Codes.

- Good resistance to fireside corrosion.

- Lower chromium content (11.5%) than austenitic stainless steel.

- No other "critical" material content.

Very approximate maximum allowable stresses, based on Section

VIII, Division 1 of the ASME Boiler and Pressure Vessel Code are

compared in Figure 9 with those of commonly used boiler tube

materials and the modified 9Cr-lMo-L1 steel under development by

Oak Ridge National Laboratory and Combustion Engineering. HT9

is not quite so strong as the modified 9Cr-lMo, but it has given

good service in superheater tubes in Europe where it has demonstrated better resistance to fireside corrosion than Type 304 stainless

steel. Frankly, it makes sense to utilize HT9 in this country right

now regardless of the chromium supply situation.

SUMMARY

Tungsten has been neglected as an alloying element in many

systems because of its volatile commercial history and belief that

most of our supply comes from Asia. We in AMAX believe that

tungsten will find many uses and will be a useful substitute for

many of the critical elements. Some of the suggestions made in

this presentation are being included in on-going programs in our

Ann Arbor Research Laboratory. Hopefully, some of these will come

to fruition in time to help better define this country's critical

material alternatives and to plan a practical substitution program.

P38-7
- 8 -

In our opinion, the Government can help most by providing

a business climate wherein natural market forces can correct supply

aberrations such as occurred in the cobalt industry and new sources

of supply can be developed. After all, as many a good geologist

has said, "Show me a shortage and I will soon give you an oversupply" .

P38-8
REFERENCES

1. K. J. A. Kundig, The Tungsten Market - From Chaos to Stability,

J. Metals, May, 1981.

2. C. C. Clark and J. B. Sutliff, Current and Future Tungsten

Supplies, Presented at Second Charlottesville Conference on

High Energy KE Penetrator Materials, Charlottesville, VA,

October 14-17, 1980.

3. Bundesanstalt fur Geowissenschaften und Rohstoffe, Hannover,

Fed. Rep. of Germany, Deutsches Institut fur Wirtschaftsforschung

,

Berlin, September 1977.

4. R. E. Schwer, Critical Materials and the Need for a Materials

Policy, Presented at ASME Gas Turbine Conference, New Orleans,

LA, March 10, 1980.

5. H. S. Kalish, An Update - New Developments in Cutting Tools,

International Conference on Cutting Tool Materials for the 80' s,

Purdue University, Lafayette, IN, June 1980.

6. J. G. Baldoni, State of the Art in Coated Carbides, The Carbide

and Tool Journal, November-December 1980.

7. B. F. Kieffer and E. F. Baroch, Recycle of Tungsten Carbide

and Mill Scrap, Presented at AIME Annual Meeting, Chicago IL,

February 23-25, 1981.

8. C. C. Clark, Practical Substitutions for Cobalt Base Superalloys,

ASM Westec Conference, March 19, 1979.

9. Report on Investigation of Direct Iron Making by High Temperature

Reducing Gas, Association for Atomic Energy Iron Making, Ministry

for International Trade and Industry, Japan, March 1981.

10. L. Egnell and N. G. Persson, On The Creep Properties of Sandvik

HT7 and HT9 , Presented at International Conference on Ferritic

Steels for Fast Reactor Steam Generators, London, 1977.

11. M. K. Booker, V. K. Sikka and B. L. P. Booker, Comparison of

Several High-Chromium Ferritic Steels, ORNL/TM-7500 , October 1980.

P38-9
TABLE 1 TUNGSTEN MINE EXPANSIONS AND OPENINGS

BETWEEN 1975 AND 1980

(Millions Pounds Tungsten /Year)

COMPANY MINE LOCATION

DATE EXPANOED

OR OPENED!*) ESTIMATED PRODUCTION

1975 1110

INCREASE

1975-1910

Canada Tungsten Cantung Canada 1976-79 2.6 7.3 4.7

King Is. Scheelite King Is. Australia 1975-77 2.7 4.5 1.8

Queensland Wolfram Mt. Carbine Australia 1977 0.2 1.6 1.4

Wise Thailand Thailand 1978 1.5 3.9 2.4

Misc. Bolivia Bolivia 1975 0.2 1.5 1.3

Metallgesellschaft Mittersill Austria 1976* - 2.7 2.7

Pacific Copper Glen Innes Australia 1979* - 1.3 1.3

Union Carbide Emerson Nev. U S. 1978* - 1.0 1.0

Union Carbide Boca De Laga Brazil 1977* - 1.0 1.0

Teledyne Wah Chang Strawberry Calif. U S. 1978* - 0.9 0.9

Total 7.2 25.7 18.5

Western World Total 41.4 60.6 19.2

9/80

TABLE 2

TUNGSTEN MINE EXPANSIONS AND OPENINGS

BETWEEN 1980 AND 1985

(Millions Pounds Tungsten/Year)

ESTIMATED

DATE EXPANDED PRODUCTION INCREASE COMPANY MINE LOCATION OR OPENED 1980 1985 1980-19

AMAX Mactung Canada Open 1984 — 7.1* 7.1 AMAX Hemerdon** U.K Open 1985 — 4.0 4.0

Brunswick Tin Mount Pleasant Canada Open 1982 — 3.2 3.2

General Electric Springer Nev. U.S. Open 1982 — 1.6 1.6

Union Carbide Emerson Nev. U.S. 1981 1.0 2.0 1.0

Total 1.0 17.9 16.9

Total Western World 60.6 76.6 16.0

'Initial Capacity

"Preliminary Feasibility Estimate

P38-10
TABLE 3

WORLD TUNGSTEN RESERVES3

(1000 metric tons)

PEOPLE’S REPUBLIC OF CHINA

CANADA

SOVIET UNION

NORTH KOREA

U.S.

AUSTRALIA

SOUTH KOREA

BRAZIL

BOLIVIA

OTHER COUNTRIES

TOTAL

*AMAX REVISION 1981 -

KNOWN & PROBABLE POTENTIAL

RESERVES RESERVES

952.6 1,814.4

245.0* 317.5

215.0 261.3

113.4 136.1

108.9 326.6

65.0 75.0

45.4 79.8

42.0 19.3

40.0 83.9

215.2 282.5

2,032.5 3,396.4

.0

TABLE 4

ESTIMATED CARBIDE RECYCLING BY CEMENTED

CARBIDE APPLICATION

PROBABLE

THEORETICAL PRACTICAL

APPLICATION MAXIMUM • % LIMIT - % CURRENT

CUTTING TOOL INSERTS 95 60 40

BRAZED TOLLS 75 40 15 OIL DRILLING 90 85 80 COAL MINING 65 50 15 MINING 85 85 65 WEAR PARTS 90 85 80

P38-11
TABLE 5 PROPERTIES OF COBALT-FREE EATONITE DIESEL ENGINE

VALVE SEAT INSERT

COMPOSITION EATONITE Co-FREE EATONITE

c 2.3 2.3 Cr 29 29 W 15 15

Fe 8 8 Co 10 —

Ni Bal Bal

Tensile Strength 50,000 PSI 53,000 PSI Elongation 0 5% 1.3%

Stress for 100 Hr Rupture at 1400 F Hot Hardness

30.000 PSI 26.000 PSI

RT 46 HRC 42 HRC

800 F 42 37 1000 F 34 37 1200 F 33 27

Coeff of Expansion RT - 1400 F 7.9 x lO'VF 7 4 x 10*/F Adhesive Wear at 800 F -2.2 mg -1.4 MG

-3.0 MG

MM LBS

W

FIGURE 1.

P38-12
US $/LB

W CONT’D

WESTERN WORLD

TUNGSTEN ORE PRICE TRENDS USS/STU

- 200

- 180

FIGURE 2.

WESTERN WORLD MINE PRODUCTION

OF TUNGSTEN

FIGURE 3.

P38-13
MM Lbs WESTERN WORLD TUNGSTEN

W

' CONSUMPTION vs. MINE PRODUCTION

Probable

GSA

Scheduled

Production

FIGURE 4

NORTH AMERICAN

SUPPLY/DEMAND OUTLOOK

FIGURE 5.

P38-14
USEAGE OF VARIOUS CUTTING TOOLS

AND THEIR SPEED RANGES

FIGURE 6.

CEMENTED CARBIDE SCRAP

DIRECT REUSE

(SOLID SCRAP AND CLEAN POWDER)

CHEMICAL RECOVERY

(CONTAMINATED OR UNKNOWN COMPOSITION)

READY TO PRESS READY TO PRESS ENERGY CONSUMPTION 3 6 KWH/Kg

(ZINC PROCESS) RECOVERY OF COMPONENTS

RECOVERY OF COMPONENTS

FIGURE 7.

P38-15
RUPTURE STRENGTH OF JAPANESE HTGR

ALLOY COMPARED WITH ALLOY 617

FIGURE 8.

MAXIMUM ALLOWABLE STRESSES FOR

SEVERAL FERRITIC STEELS BASED ON ASME

CODE SECTION VIII DIV 1.

c/>

</> UJ

GCH

(f) LUm

<O w

-J CL

os

x

<

5o

to

TEMPERATURE, (C) FIGURE 9.

P38-16
NEW APPLICATIONS OF VANADIUM IN STEELS

TO SAVE COST, ALLOYING AND ENERGY

P. L. Mangonon

Foote Mineral Co.

P39

1

FASRAD 81-4

New Applications Of Vanadium In Steels

To Save* Cost , Alloying And Energy*

by

P. L. Mangonon

Manager, Steel R&D

Foote Mineral Co.

Route 100

Exton, PA. 19341

Abstract

New applications of vanadium in heat-treated and as-forged

steels are indicated where considerable savings in costs, alloying and energy might be realized. In the heat-treated steels,

the substitution of one-part vanadium for two-parts of molybdenum

was shown to be effective both in the laboratory and in commercial parts. In the laboratory, it was also shown that a favorable interaction of Mo and V exist when both are present in steel

which offers economic advantages. Applications of as-forged

automotive components made with vanadium microalloyed steels

offer cost and energy savings.

* Presented at the Workshop on Conservation and Substitution

Technology for Critical Materials June 15-17, 1981,

Vanderbilt University, Nashville, Tennessee.

P39-1
2

j-ntroduction

During the seventies, the vulnerability of the United

States with regards to critical materials and energy was exposed. This has led to the establishment of the National

Minerals and Materials of 1980 Policy. In addition, as a result of the shortages, conservation and substitution of materials

and energy were very common. This paper points out the new

applications of vanadium to save materials, energy and cost.

Applications of Vanadium in Constructional Alloy Steels

Constructional alloy steels are principally used for structural members of moving vehicles, i.e. automobiles, aircraft

and off-highway vehicles, as well as oil-drilling and farm equipments requiring quenching and tempering. In 1980, an examination

of the SAE alloy steel compositions reveals that only two standard steel grades, 6118 and 6150, contain vanadium out of the 86

listed. In this same handbook are listed 96 formerly standard

SAE alloy steels, 11 of which contain vanadium. It is obvious

that the application of vanadium in alloy steels has declined in

recent years.

However, the history of alloy steel usage in this country

shows that vanadium steels were prominently used in the automotive industry. Figure 1 shows that the usage of vanadium

peaked in 1920 and has been in constant decline since. The

principal replacement for vanadium in alloy steels was molybdenum

and the principal reasons for the replacement were availability

and price^^ - the same subjects that this workshop is concerned

P39-2
3

about. In the early 1900 ' s Peru was a substantial supplier of

vanadium. The vanadium mine was located in a remote area

in western Peru and its development was indeed costly. When

the site was first developed, the nearest railroad was 24.5

tortuous miles, not intended for vehicles carrying the ore.

To haul the ore, llamas were used until 1920 when a narrow

gauge railroad was laid. The ores were concentrated to essentially vanadium pentoxide and then shipped to Bridgeville,

Pennsylvania where they were converted to f errovanadium as the

alloying additive to steel.

Compared to molybdenum which is in abundant supply in this

country, vanadium has until recently been traditionally higher

in price than molybdenum. As late as 1973, vanadium cost twice

as much as molybdenum. It is not altogether surprising that

molybdenum vis-a-vis vanadium established itself in alloy steels

because of economics and availability. Figure 2 depicts the

takeover of molybdenum from vanadium in alloy steels to the extent that in 1980, 56 out of 86 listed SAE standard alloy steels

contain molybdenum - all but four contain less than 0.30% Mo.

Inspite of this seemingly small percent addition, molybdenum

consumption in alloy steels has been about 46-50% of its total

consumption - the major portion of its market.

The second half of the seventies showed a great demand for

molybdenum, putting pressures on supply and depleting inventories. The result was the tremendous surge in molybdenum price

such that in 1979 this exceeded the price of vanadium for the

P39-3
4

first time. There was in fact a three-tier pricing - the official domestic price, the export price and the "free market"

price which were rumored to go as high as $30.00 a pound.

Steel producers were forced to pass on to customers molybdenum

sur-charges to compensate for their costs.

The situation just described provided an opportunity for

vanadium to be applied again in alloy steels. Unfortunately,

there was insufficient information in the literature about vanadium usage in heat treated steels. The information available

was confused and conflicting and was done without regards to

possible alloy interactions.

In an effort to determine the real effects of vanadium in

alloy steels, the basic hardenabilities of medium-carbon standard

alloy grades modified with vanadium were studied. The results

(4,5,6) substantiated earlier results on mild steel^^ that vanadium is twice as potent as molybdenum in increasing hardenability. Translated in another way, it was demonstrated that

one weight percent of vanadium can be substituted for two weight

percent of molybdenum to attain the same hardenability . In

these studies, 0.30% molybdenum can be replaced by 0.15% vanadium with the standard modification in heat-treatment v J or

with 0.10% V and 0.10% Mo using the normal specified SAE^^

austenitizing temperature based on carbon content. These results were obtained in alloy steels containing 0.15-0.40%C which

correspond to what most of the alloy steel grades contain.

A significant finding of these studies is the apparent

P39-4
5

beneficial synergistic mutual interaction effect of molybdenum

and vanadium when both are present together in the alloy. For

example, the substitution of 0.10% V and 0.10% Mo for the

0.30% Mo standard composition yielded an ideal critical diameter

(hardenability ) in excess of that exhibited by the standard. In

analyzing this situation, the addition of the individual

effects of molybdenum and vanadium did not sum up to the change

in hardenability when both are present together. However, when

analyzed statistically

)

the results show that the individual

effects were much higher than those obtained experimentally

and they added up to the total experimental effect of Mo and V

together. This apparent discrepancy can be rationalized with

the suggestion that when both are present , each of the element

exerted mutually beneficial interaction effect by raising the

other element's individual hardenability factor.

Some practical suggestions are being made regarding this

interaction effect. It is possible for example to take advantage

of the molybdenum content in scrap to yield acceptable residual

molybdenum contents in steel up to 0.06% and alloy this with

0.10-0.15%V to yield the same results as the 0.30% Mo grade.

It is also being suggested that the mutual interaction effect

induced by vanadium is in fact equivalent to a 1:3 vanadium-formolybdenum. Both suggestions offer tremendous material and cost

savings.

Independent of the studies cited so far, Republic Steel had

embarked on a similar program earlier that led to the very recent

P39-5
6

commercialization of a Ni-Cr-V steel which is being used in an

automotive part . ^ ; The results of this work support the laboratory results cited above and while specifically not mentioned,

the resultant Ni-Cr-V steel developed is a modified 4320 with

molybdenum completely substituted by vanadium in the 1:2 proportion mentioned earlier. In addition, the properties and performance of this steel approached those of higher nickel grades

which can lead to a substantial cost effective substitute for

these standard higher nickel alloy steels. The most significant

addition of this study is the demonstration that structural

components made from vanadium modified grades can be carburized

and give performance as good or better than higher alloy grades.

Commercialization of this alloy was made possible by much

earlier work on substitution by Republic Steel and its customer.

The molybdenum supply-demand in the late seventies boosted this

option to be taken from the shelf. The compositions of the

laboratory heats examined are shown in Table I and Figure 3

shows the hardenability of this Ni-Cr-V steel relative to some

of the steels listed in Table I. Carburizing of the steels

was examined using the three cycles shown in Table II. The properties of all steels examined were generally better using cycle

C and it is significant that the performance of the newly developed

Ni-Cr-V steel was attained without much difference or special

modification from those used for the other steels.

The hardenabilities of samples from commercial Ni-Cr-V steel

heats compare very favorably with the published 4620-H and 4815-H

bands shown in Figures 4 and 5, respectively. The hardenability

P39-6
7

band of the Ni-Cr-V lies generally on the high side of the 4620-H

which is the steel it was intended to replace and within the

broader 4815-H band which has the higher 3.5% nickel. The average composition of the commercial heats are shown in Table III

together with those of 4620 and 33L10 whose properties were

compared with the newly developed Ni-Cr-V steel. The carburized

properties are shown in Tables IV, V and VI and demonstrate the

superiority of the Ni-Cr-V over the 4620 alloy.

Applications of Vanadium in As-Forged Automotive Parts

Many automotive components such as crankshafts, connecting

rods and suspension components are produced from hot-forged

bars which are commonly heat-treated to obtain the necessary

properties. Typically, the steels used are medium carbon-manganese

steels. Recently, it was discovered that micro-alloying additions

of vanadium or columbium to these grades ( ^ ^ ^ enable the steel

to attain the desired properties in the as-forged condition. The

elimination of the heat-treating provides a significant cost

saving as well as conserving energy.

In this country, applications of as-forged components cited

above has not caught on as much as in Japan and Europe because

the substitution of quenched and tempered martensite structures

by pearlitic malleable pearlitic nodular cast irons was underway.^)

The reason for the difference in approach in the U.S. and in

other countries is not entirely clear. Suffice it to say, that

as-forged connecting rods, crankshafts and suspension components

are commercially made in the as-forged condition.

P39-7
8

In both Japan and Europe, the predominant micro-? cloying

addition for as-forged applications is vanadium. Initial

development studies between Honda Motors and Daido Steel (12)

in Japan indicate the importance of the as-forged hardness. The

dependence of this as-forged hardness to composition was obtained

by regression analysis and was shown to be

Heq = 4.70 + 32 . 5(%C) + 1.04(%Si) + 4.14(%Mn)

1 . 54(%Cr ) 66 . 6(%V) + 10.8(%Nb) +

1 8 3 ( %N ) - -- -- -- -- -- -- -- -- - (i)

where Heq

is the equivalent hardness in Rc based on the specified

forging conditions. v ' The regression equation was found to

have a multiple correlation coefficient of R=0.983. Carbon

and vanadium were considered the elements contributing significantly to the hardness. Based on this, a recommended range of

composition of carbon and vanadium is shown shaded in Figure 6.

The final composition of the steel selected depends on the properties but the vanadium content is limited to less than 0.2%

for economy.

The hardness of the resultant component depends also on

the soaking temperature before forging as well as on the cooling

rate and mass of the component after forging. Thus, based on the

same Heq , the resultant component hardness can vary as shown in

Figure 7. Higher soaking temperatures allow the vanadium to be

dissolved in austenite and possibly allow the austenite grains

to coarsen. Vanadium in solution and the enlarged austenite

grains enhances the hardenability of the steel. Vanadium in

solution in austenite lowers also the transformation point to

P39-8
9

induce finer f errite-pearlite structures on transformation. In

addition, the vanadium in solution in austenite will be the

source of further strengthening when the vanadium precipitates

as fine particles in ferrite. The faster the cooling rate and

lesser the mass of the component after forging, the harder will

be the resultant hardness. In contrast, at lower soaking temperatures when vanadium is left undissolved in austenite, the desired strengthening effect of vanadium cannot be well demonstrated.

A comparison of tensile properties of as-forged vanadium

micro-alloyed steels with those of the conventional quenched and

tempered (Q+T) free-machining steels is shown in Table VII. The

compositions, forging, and Q+T conditions of the steels are also

given. The properties are seen to be very comparable.

Examples of parts made from the microalloyed steels are

shown in Figure 8. Machinability and fatigue properties of the

components are as good or better than the conventional Q+T steels.

In addition, the uniformity in properties (hardness) across the

sections of the parts is much better than the Q+T steel.

The microstructures of the as-forged components show typically

pro-eutectoid ferrite outlining the previous austenite grain

boundaries with pearlite in the interior. Consequently, in comparison to the Q+T structure which do not show this outline,

the ductility and impact properties are inferior to Q+T. However,

these deficiencies do not seem to be critical since the controlling

property appears to be fatigue/ 2 ’ 13 ’ 14 ) A comparison of fatigue

properties of crankshafts^ 1 ^) made with a microalloyed steel

P39-9
10

49MnVS3 (0.47C, 0.34Si, 0.77Mn, 0.053S, 0.12V and 0.0078N) and

with a grade similar to SAE 1046 is shown in Figure 9. This

illustrates the superiority of the microalloyed steel at lowcycle fatigue and a respectable fatigue strength (high cycle

fatigue) considering that the tensile strength of the microalloyed steel was slightly lower. (13) The reason f0 r this is

that the monotonic tensile properties do not enter into consideration during fatigue, although empirically the fatigue limit is

related to tensile strength. The important properties are determined by the cyclic stress-strain curves and these show that

the Q+T structures exhibit significantly more cyclic softening

than do the f errite-pearlite structures. As illustrated in

Figure 10, the monotonic yield strengths of the Q+T and the

microalloyed as-forged steel are about equal. The cyclic stressstrain curves reveal however that the Q+T cyclically softens more

and cyclically work hardens less than the as-forged micro-alloyed

steel. In other words, the microalloyed steel is capable of

carrying more cyclic load at a particular cyclic strain.

The successful application and performance of microalloyed

as-forged components illustrate also the role of critical evaluation of the controlling behavior of components in structures.

Outright rejection of the microalloyed steel based on lower

ductility and impact toughness, which most people do, would not

have led to the observed savings in cost and energy. There is

probably myriads of situations similar to the situation here

where comparable savings in cost and energy can be realized if

P39-10
11

the critical evaluation is made.

Summary and Conclusions

An attempt was made to illustrate new applications of vanadium in heat-treated steels as well as in as-forged steels.

Both offer tremendous savings in cost, material and energy.

In the heat-treated steels, heretofore misconceptions on the

influence of vanadium on hardenability were hopefully dispelled

both by laboratory results and by the successful commercialization

of an economical steel with very good performance. In the asforged steels, the strengthening effect of vanadium through

precipitation of carbo-nitrides was taken advantage of. The

successful application of the steel in components illustrate the

need to critically evaluate how the component fails in service

if we are to save costs and energy.

P39-11
References

1. SAE Iron and Steel Handbook Supplement HS30, 1980.

2. G. H. Robinson, "The Future of Alloy Steels in the Automobile"

p. 1 of "Alloys for the Eighties" R. Q. Barr, Editor, Climax

Molybdenum Company, Proceedings of symposium held in Ann Arbor,

MI., June 17-18, 1980.

3. Vanadium, Foote Prints , p. 18 Volume 42, No. 1, 1976. (A publication of Foote Mineral Company, Exton, PA.)

4. P. L. Mangonon, "Hardenabilities of Vanadium-Modified 4330

Low Alloy Construction Steels" Journal of Heat Treating 1 No. 4

In Press.

5. P. L. Mangonon, "The Heat-Treatment of Vanadium Modified Alloy

Steels" Journal of Metals, June, 1981. In Press.

6. P. L. Mangonon, Relative Hardenabilities and Interaction Effects

of Mo and V in 4330 Alloy Steel, submitted for publication to

Metallurgical Transactions A.

7. R. A. Grange, Metallurgical- Transactions 4A, (1973) pp . 2231-

2244.

8. R. B. Bertolo, R. T. Ault and R. H. Cobbett , "A New High Performance, Cost Effective, Carburizing Grade Alloy Steel",

SAE Paper 810424, presented at the Annual SAE Congress, Detroit,

Michigan, February 23-27, 1981.

9. J. H. Bucher, J. F. Held, & J. F. Butler - "Micro-alloyed Bar

Products", SAE Paper 790026, presented at the Annual SAE Congress

.

Detroit, Michigan, February 26-March 2, 1979.

10. J. H. Bucher, J. H. Held, & J. F. Butler, "Micro-alloyed Bar

Products" p. 47 in Vanadium in High Strength Steel, Proceedings

of a VANITEC Seminar in Chicago, Illinois, November, 1979.

11. S. Niwa, et . al .

,

Research and Development of Micro-alloyed

Medium Carbon Steels, SAE Paper 810426, presented at the Annual

SAE Congress, Detroit, Michigan, February 23-27, 1981.

12. C. Razim, Use of Medium Carbon Micro-alloy Steel in Fatigued

Strengthened Structural Parts, Metal Progress, May, 1981. p. 50.

13. D. Whittaker, Micro-alloyed Medium Carbon Steels for Forging,

Metallurgia

,

April, 1979, p. 275.

P39-12
13

List of Tables & Figures

Table I. Compositions of Laboratory Heats

Table II. Carburizing Cycles

Table III. Compositions of Commercial Heats

Table IV. Pseudocarburized Properties of Commercial Heats

Table V. Carburized Impact Properties of Commercial Heats

Table VI. Carburized Fatigue Properties of Commercial Heats

Table VII. Mechanical Properties of As-Forged Microalloyed, and

Quench-Tempered Conventional Free-Machining Steels

Figure 1. Alloy Steel Production in the U.S. Showing Cumulative

Percent of Steel Type Produced in a Given Year from 1900

Figure 2. Relative Percent of Alloy Steels Produced Containing V

or Mo During Same Period as Fig. 1

Figure 3. Hardenability of 6118, 4620, 4718, 4320 and Ni-Cr-V

Laboratory Heats

Figure 4. Hardenability Range for 15 Commercial Heats of Ni-Cr-V

Compared to the 4620-H Band

Figure 5. Hardenability Range for 15 Commercial Heats of Ni-Cr-V

Compared to the 4815-H Band

Figure 6. Influence of C and V Contents on Hardness Equivalence

Figure 7. Correlation of Hardness Equivalence and Hardness of

Actual Components after Forging

Figure 8. Examples of Forgings of Microalloyed Steels

Figure 9. Comparative Fatigue Resistance of SAE 1046 and 49 MnVs 3

Crankshafts for Diesel Engines

Figure 10. Cyclic Stress-Strain Curves of Microalloyed Steel and

Quenched and Tempered Steel Showing Cyclic Softening

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P39-13
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P39-20
World

World

Korean

War I

War

II

Emergency

21

P39-21

Fig.

1.

Alloy

Steel

Production

in

the

U.S.

Showing

Cumulative

Percent

off

Steel

Type

Produced

in

a

Given

Year

from

1900.
22

oiai jo a 6uju;e)uoo

paonpojd S|99js Aohv %

P39-22

1900

1910

1920

1930

1940

1950

1960

1970

Calendar

Year

Relative

Percent

of

Alloy

Steels

Produced

Containing

V

or

Mo

During

Same

Period

as

Fig.
4320

a

4718

23

P39-23

Distance

From

Quenched

End

-

1/16"

Hardenability

of

6118/

4620/

4718/

4320

and

Ni-Cr-V

Laboratory

Heats
24

P39-24

Distance

From

Quenched

End

-

1/16"

Hardenability

Range

for

15

Commercial

Heats

of

Ni-Cr-V

Compared

to

the

4620-H

Band,

-

-

_

-

—
25

°y - ssaupjBH

P39-25

Distance

From

Quenched

End

-

1/16"

Fiq,

5

.

Hardenability

Range

for

15

Commercial

Heats

of

Ni-Cr-V

Compared

to
C

Content

(wt

%)

26

Fig. 6

Influence Of C And V Contents

On Hardness Equivalence

Note: Other Alloying Elements Si: 0.25%, Mn: 0.75%, N: 0.01%

P39-26
27

o

LL_

P39-27

Hardness

Equivalence:

Heq
28

Fig, 8

Examples of Forgings of Microalloyed Steels

( a ) Connecting rod and connecting rod cap

( b ) Suspension component

( c ) Suspension component

P39-28
Comparative

Fatigue

Resistance

Of

SAE

1046

And

49

MnVS

3

Crankshafts

For

Diesel

Engines.

Minimum

Load:

5

kN

(1120

lb).

29

LO r- h- n

if)

\

LO LO CO ^

(qi eOi.) n>i ‘peon

T~

LO CM LO n

ID -O

P39-29

Number

Of

Cycles
Cyclic

Stress-Strain

Curves

of

Microalloyed

Steel

and

Quenched

and

Tempered

Steel

30

n Oi 1 BEGffi c c

o o

o « o .2

= 0 = 0

o >, o >

S O S O

< • o

(zujuj/n) ‘DV^ssaiis

P39-30
NEW RECLAMATION PROCESS FOR CRITICAL METALS

William J. Boesch

Special Metals Inc.

P40

New Reclamation Process

for

Critical Metals"

Presentation

for

Special Metals Corporation

by

W. J. Boesch

Associate Director - Technology

Special Metals Inc.

at

Workshop on Conservation and Substitution Technology

for

Critical Materials

15-17 June 1981

Vanderbilt University, Nashville, Tennessee

Sponsored

by

U. S. Department of Commerce/NBS

U. S. Department of Interior/Bureau of Mines

Participation

wi th

U.S. Department of Defense

National Aeronautics and Space Administration

P40-1
INTRODUCTION

Raw material shortages impact business in three fundamental modes:

Economic (can live with); Economic/Geopolitical (can live with, if supply

is diverse and available to the country requiring the supply); and Economic/ World Resource (severe problem since this [Tantalum Example] is

closest to a depletion problem). Although the general increase in element

costs pose some business problems, we can pass those and address the more

serious problems. The United States has a very high import reliance on

many strategic elements such as chromium and cobalt. Sensitive geopolitical situations can precipitate shortages, may strongly impact the vital

interests of the United States and may even threaten National Security.

There also exists the imposing specter of a general lack of world resources

with elements such as tantalum. This really poses a challenge to the aerospace, petrochemical, and defense-related industries. Conservation is

suggested as a means of alleviating the problem. This methodology usually

involves restriction in usage and recycling. Current and newly proposed

recycling processes have certain inherent shortcomings. Generally, recycling

incorporates collection, processing, remelting, and refining of segregated

scrap which has chemical formulations compatible with the desired alloy.

These techniques usually have minimum flexibility and may inherently introduce contamination and non-compatible alloys which can decrease properties or

render the desired alloy useless, especially in high technology applications.

Scrap identification, analysis , isolation, and storage difficulties do not

create an ideal zero-defect environment. An attractive optional methodology is to utilize reclamation of critical elements. To clarify a point,

we must define what we mean by "Recycling" and "Reclamation." Basically

we suggest that:

P40-2
- 2

-

• Recycling involves manufacturing of superalloys,

utilizing segregated scrap which has chemical

formulations compatible with the desired alloy;

whereas

,

• Reclamation involves processing of miscellaneous

scrap which contains strategic elements to be

recovered in pure form.

The development, construction, and operation of an integrated reclamation plant for recovery of strategic elements from industrial waste and scrap

could provide the most reliable and flexible supply of critical elements.

The attached flow sheets detail a typical operation and summarize the

benefits

.

PROPOSAL

It is proposed to integrate various metallurgical technologies in the

recovery of elemental metals from superalloy and stainless steel scrap.

The recovered metals are to be suitable for aircraft, aerospace and other

defense-oriented applications. A production-scale process study will demonstrate the technology using commercially available operating equipment. In

this way, cost estimates can be derived from production rather than extrapolated pilot plant experience.

Special Metals has been conducting dissolution and extraction experiments at the Arizona Bureau of Geology and Mineral Technology, in conjunction

with the University of Arizona. Using Waspaloy grinding dust, a process

has been devised to recover cobalt, molybdenum, nickel, and chromium. A

pilot plant stage to verify the feasibility of the process is necessary,

to verify existing data.

P40-3
-3-

A project team will be formed to carry out the unit operations in

sequence. The operations will include furnacing (to result in oxidization

and carburization of the scrap) ,atomi zation, dissolution, solvent extraction,

chemical precipitation, electrowinning, and hydrogen reduction. Where

possible, existing commercial equipment will be used. This approach will

result in more accurate process parameter evaluation and cost estimates than

those extrapolated from prior studies. The metals recovered will be analyzed

to verify their suitability for aircraft applications. This suitability will

be demonstrated by the evaluation of representative superalloys prepared from

the reclaimable metals. A cost effective plant will be designed and constructed .

Application of such technologies to superalloy and stainless steel scrap

will increase the availability of strategic materials and thereby lessen

dependence on foreign imports. Demonstrating that the technique is costeffective on a production scale is expected to spur the establishment of

integrated facilities within the metals industry.

SUMMARY:

Successful completion of the proposal will result in increased availability of strategic materials in elemental form, thus:

• Decrease Import Reliance on Strategic Elements

* Increase the Flexibility for Reclaimed Element Use

P40-4
METALLURGICAL WASTE & SCRAP

INPUT

CONCENTRATES

Oxide / Salte

P40-5
P40-6
PILOT PLANT STUDY

Estimated Financial Balance

Processing of 2500 lbs. of Waspalloy waste per day

for 330 days per year operation

Capital $2,000,000

Operation $3,500,000

Recovered Metal Values

Chromium (72 tons ppt.)

Nickel (210 tons metal)

Cobalt (50 tons metal)

Molybdenum (15 tons ppt.) $4,600,000 . , _^ ^ ^

P40-7
THE ROLE OF COMPOSITES IN SUBSTITUTION, CONSERVATION AND

DISPLACEMENT OF CRITICAL MATERIALS

Alfred E. Brown

Celanese Corn,

P41
KEYNOTE ADDRESS

THE ROLE OF COMPOSITES IN SUBSTITUTION, CONSERVATION

AND DISPLACEMENT OF CRITICAL MATERIALS

BY

Dr, Alfred E, Brown

Director, Scientific Affairs

Celanese Corporation

PRESENTED AT

The Workshop on Conservation and Substitution

Technology for Critical Materials

Vanderbilt University

Nashville, Tennessee

June 17 , 1981

P41-1
This morning I'd like to discuss the role of composites in

SUBSTITUTION, CONSERVATION AND DISPLACEMENT OF CRITICAL MATERIALS.

AS WE ' RE LEARNING IN THIS WORKSHOP, THERE ARE SEVERAL ROUTES TO

REDUCE THE DEMAND ON CRITICAL MATERIALS. ONE SUCH ROUTE IS

THROUGH THE REPLACEMENT OF METALS WITH STRUCTURAL COMPOSITES.

Since the structural composites industry is entering a period

OF EXPLOSIVE GROWTH (COMPOUNDED GROWTH RATES OF 25-30%/YEAR

ARE ANTICIPATED FOR THE 80'S) THE POTENTIAL IMPACT ON CONSERVATION OF CRITICAL MATERIALS IS VERY SIGNIFICANT. THEREFORE,

IT'S IMPORTANT TO UNDERSTAND THE MAGNITUDE AND RAMIFICATIONS

OF COMPOSITE REPLACEMENT IN ORDER TO PROJECT THE IMPACT ON

MATERIALS CONSERVATION. TO ACQUIRE THIS UNDERSTANDING, IT'S

NECESSARY TO APPRECIATE THE NATURE AND CHARACTERISTICS OF THE

UNDERLYING COMPOSITES INDUSTRY.

The rationale for the rapid growth of the composite industry is

THE URGENT NEED FOR MORE FUEL EFFICIENT TRANSPORTATION AND THE

PROVEN ABILITY TO SUBSTITUTE LIGHTWEIGHT COMPOSITE STRUCTURE

FOR HEAVIER TRADITIONAL METALS BECAUSE OF THE HIGHER PERFORMANCE

PROPERTIES OF GRAPHITE COMPOSITES. THIS REPLACEMENT OF METALS

WITH COMPOSITES PROVIDES TWO ROUTES TO REDUCE DEMAND FOR

CRITICAL MATERIALS. THE FIRST IS DIRECT SUBSTITUTION OF

COMPOSITES FOR CRITICAL METAL STRUCTURE, WHEREAS, THE SECOND

RESULTS FROM SECONDARY CASCADING EFFECTS WHEN A COMPONENT

WITHOUT CRITICAL MATERIALS IS DIRECTLY DOWNSIZED. HAVING

P41-2
- 2 -

INDICATED THE RELEVANCE OF COMPOSITES IN REDUCING THE DEMAND

FOR CRITICAL MATERIALS, I'D LIKE TO REVIEW BRIEFLY COMPOSITES

AS REPLACEMENT MATERIALS.

In discussing composites and their role as substitution

MATERIALS, I THINK IT'D BE BENEFICIAL TO START OFF WITH A GENERAL

REVIEW OF THE USE AND PERFORMANCE CHARACTERISTICS OF COMPOSITES

FOLLOWED BY A DISCUSSION OF THE GENERAL NATURE OF THE COMPOSITE

INDUSTRY. I THEN INTEND TO DISCUSS COMPOSITE END-USE APPLICATIONS

IN THE AEROSPACE/AIRCRAFT INDUSTRY AND IN VARIOUS AUTOMOTIVE/

INDUSTRIAL APPLICATIONS. THE PRIMARY THRUST OF MY COMMENTS IN

THIS SECTION, HOWEVER, WILL BE DIRECTED TOWARDS AEROSPACE/AIRCRAFT

BECAUSE THAT'S WHERE THE MAJOR GROWTH AND REPLACEMENT OPPORTUNITIES

WILL OCCUR IN THE 1980 'S. SIGNIFICANT GROWTH IN THE AUTO/

INDUSTRIAL SECTOR IS NOT PROJECTED TO OCCUR UNTIL THE LATE 1980 'S.

The first slide (Figure 1) has a definition for structural

composites. Basically, structural composites are products which

COMBINE VERY HIGH STRENGTH AND STIFFNESS, LOW DENSITY FIBER

REINFORCEMENTS (E.G., CARBON, ARAMID, GLASS, BORON) WITH CONVENTIONAL POLYMERS OR METALS (E.G., EPOXY, POLYESTER, POLYIMIDE,

ALUMINUM) TO FORM STRUCTURAL MATERIALS WITH UNIQUE PROPERTY

CHARACTERISTICS. THE HIGH FIBER LOADINGS (TYPICALLY 50 - 70%

BY WEIGHT, INDICATED ON THE SLIDE), ARE REQUIRED TO SIMULTANEOUSLY MAXIMIZE PERFORMANCE LEVELS AND WEIGHT SAVINGS.

P41-3
- 3

-

The motivation behind the broad based appeal that structural

COMPOSITES HAVE OBTAINED IN RECENT YEARS IS SUMMARIZED IN

THE NEXT SLIDE (FIGURE 2). FIRST, COMPOSITES HAVE UNIQUE

PERFORMANCE CHARACTERISTICS WHEN COMPARED TO METALS AND

PERFORMANCE HAS BEEN THE DRIVING FORCE IN THE SUBSTITUTION

OF METALS BY STRUCTURAL COMPOSITES, THEY COMBINE THE

IMPORTANT MECHANICAL PROPERTIES OF HIGH SPECIFIC STRENGTH

AND SPECIFIC STIFFNESS, VERY GOOD DYNAMIC RESPONSE AND EXCELLENT

CHEMICAL PROPERTIES SO THAT THEY HAVE INHERENT PERFORMANCE

ADVANTAGES OVER MOST OTHER MATERIALS, TYPICAL SECONDARY

PROPERTIES OF INTEREST INCLUDE FATIGUE RESISTANCE, CORROSION

RESISTANCE, AND LOW THERMAL EXPANSION. THE SPECIFIC SET OF

PROPERTIES AVAILABLE, DEPENDS, OF COURSE, ON THE COMBINATION

OF FIBER AND MATRIX UTILIZED, SECOND, COMPOSITES OFFER DESIGN

FLEXIBILITY AND SIMPLIFICATION, By VIRTUE OF THEIR ANISTROPIC

NATURE, HIGH PHYSICAL PROPERTIES ARE DEVELOPED IN THE COMPOSITE 'S

FIBER DIRECTION DESPITE THE RELATIVELY LOW PROPERTIES OF THE

MATRIX RESIN ALONE. COMPOSITE DESIGN AND FABRICATION CAN

UTILIZE FIBER ORIENTATION AND LAYERING SEQUENCES TO GET MAXIMUM PERFORMANCE OUT OF THE MINIMUM AMOUNT OF MATERIAL. THIRD,

COMPOSITES HAVE ESTABLISHED THE NECESSARY DATABASE FOR

DEMONSTRATED PERFORMANCE RELIABILITY AND COST EFFECTIVENESS

IN THE AEROSPACE/AIRCRAFT INDUSTRY, A MAJOR TRANSFORMATION

IN THE USE OF STRUCTURAL MATERIALS IS NOW OCCURRING WiTHIN THE

AEROSPACE INDUSTRY AS THE NEED FOR MORE FUEL EFFICIENT PLANES

P'41-4
- 4 -

GROWS. I'LL SAY MORE ON THIS SUBJECT LATER. FINALLY, COMPOSITES

ALSO OFFER POTENTIAL FOR THE INDUSTRIAL/AUTOMOTIVE MARKET, BUT

MATERIAL ACCEPTANCE ON A LARGE SCALE IS STILL SEVERAL YEARS

AWAY. Key issues to be addressed here are high speed industrial

PROCESSING AND RAW MATERIAL ECONOMICS.

The next slide (Figure 3) illustrates the excellent specific

COMPOSITE PROPERTIES WHICH I ALLUDED TO A FEW MOMENTS AGO.

In this chart, specific tensile strength and specific tensile

MODULUS FOR A NUMBER OF ORGANIC MATRIX COMPOSITE MATERIALS AND

METALS ARE SHOWN. NOTE THAT THE DEFINITION OF A SPECIFIC

COMPOSITE PROPERTY IS THE ABSOLUTE VALUE OF THE PROPERTY

DIVIDED BY THE MATERIAL'S DENSITY. THE SPECIFIC TENSILE

STRENGTHS OF CARBON, KEVLAR, AND CONTINUOUS GLASS/EPOXY SYSTEMS

ARE FAR SUPERIOR TO ANY OTHER MATERIALS SHOWN ON THE CHART.

With regard to specific tensile modulus, however, carbon

fiber/epoxy systems are clearly unique and the system of choice.

The bar chart establishes at least part of the technical justification FOR COMPOSITE SUBSTITUTION IN THAT IT DRAMATICALLY

ILLUSTRATES HOW COMPOSITE MATERIALS CAN COMPETE EFFECTIVELY

AGAINST STEEL AND ALUMINUM ON A PERFORMANCE/WEIGHT BASIS.

Although the above bar chart didn't illustrate the advantages

OF METAL MATRIX COMPOSITES, THE SPECIFIC PROPERTIES ARE INTERMEDIATE BETWEEN THOSE OF THE PURE METALS AND OF THE ORGANIC

MATRIX COMPOSITES. THIS ILLUSTRATES THAT THE METAL MATRIX

COMPOSITES CAN ALSO COMPETE EFFECTIVELY WITH METALS ON A

P41-5
- 5

-

PERFORMANCE/WEIGHT BASIS BUT THE MAGNITUDE OF THE ADVANTAGE

DEPENDS UPON THE DENSITY OF THE MATRIX MATERIAL, CLEARLY,

METAL MATRIX COMPOSITES ARE UTILIZED WHERE HIGH TEMPERATURE

PERFORMANCE IS AT A PREMIUM,

Carbon fiber composites are one of the fastest growing segments

of the high performance composite business, This growth rate

is being fueled by their increasing acceptance in the aerospace

industry and by the standardization in product quality and

PRODUCT PERFORMANCE WHICH RESULTED FROM LARGE SCALE MANUFACTURE,

The next slide (Figure 4) shows some of the key performance

FACTORS IMPACTING THE USE OF CARBON FIBER COMPOSITES. ON THE

LEFT HAND SIDE, I HAVE LISTED THE MAJOR PRODUCT ADVANTAGES AND

ON THE RIGHT HAND SIDE I HAVE HIGHLIGHTED SOME OF THE CRITICAL

ISSUES WHICH MUST BE ADDRESSED IF CARBON FIBER IS TO ACHIEVE

IT'S LONG-TERM POTENTIAL, COUPLING LOW WEIGHT — COMPOSITE

PARTS TYPICALLY WEIGH 1/5 THAT OF THE WEIGHT OF A STEEL

PART -- WITH HIGH STRENGTH AND STIFFNESS, GIVES THE SPECIFIC

PERFORMANCE ADVANTAGES ALREADY MENTIONED. FATIGUE RESISTANCE

IS ANOTHER CHARACTERISTIC WHICH IS HIGHLY DESIRABLE, AIRCRAFT

LIFE, AS MANY OF YOU KNOW, IS DICTATED BY THE FATIGUE LIFE OF

THE METAL STRUCTURE, OF COURSE, HELICOPTER BLADES FALL INTO

THE SAME CATEGORY, THE OTHER ADVANTAGES (VIBRATION DAMPENING,

CORROSION RESISTANCE, FRICTION AND WEAR CHARACTERISTICS,

ELECTRICAL CONDUCTIVITY) ARE OFTEN REFERRED TO AS SECONDARY

PROPERTIES, BUT EACH CAN OFFER ITS UNIQUE SATISFACTION IN A

P41-6
6

GIVEN APPLICATION, REGARDING PERFORMANCE ISSUES THE TWO OF IMMEDIATE CONCERN TO THE AEROSPACE INDUSTRY AND OF GROWING CONCERN

TO THE AUTOMOTIVE INDUSTRY ARE COMPOSITE DURABILITY AND REPAIRABILITY. These issues need to be studied much more extensively

IN THE COMING YEARS, AND THE ULTIMATE OUTCOME COULD EFFECT THE

TIMING AND EXTENT TO WHICH COMPOSITES PENETRATE THESE KEY

INDUSTRIES, THE ISSUE OF IMPACT, OR DAMAGE TOLERANCE IS

GERMANE TO BOTH THE AEROSPACE AND AUTOMOTIVE INDUSTRIES, THE

AREA IS ACTIVELY BEING PURSUED AT THE PRESENT TIME FOR PRIMARY

COMMERCIAL AIRCRAFT STRUCTURES AND SIGNIFICANT ADVANCES IN THE

TECHNOLOGY SHOULD BE FORTHCOMING IN THE NEAR FUTURE. RECYCLING

IS AN ISSUE PRIMARILY RELATED TO THE AUTOMOTIVE INDUSTRY, AND

IT ALSO NEEDS MUCH MORE STUDY IN THE COMING YEARS.

The next slide (Figure 5) illustrates the process for making

LAMINATED COMPOSITE STRUCTURES. HIGH PERFORMANCE, CONTINUOUS

FIBERS, OR WOVEN FABRICS, ARE IMPREGNATED WITH EITHER ORGANIC

OR METAL MATRICES TO YIELD ANISOTROPIC, PRE- I MPREGNATED TAPES

OR BROADGOODS. THE PRE-PREG MATERIAL IS THEN "LAYED-UP" IN

A PREDETERMINED LAYERING SEQUENCE, PLACED IN A MOLD, AND

CURED WITH HEAT AND PRESSURE. DEPENDING UPON THE KIND OF

FIBER USED AND THE LAYUP ANGLES, IT'S POSSIBLE TO GET A

COMPOSITE AS STIFF AS BERYLLIUM OR AS STRONG AS THE HIGHEST

STRENGTH STEEL.

P41- 7
- 7

-

The next slide (Figure 6) serves to give a capsule summary of

THE KEY CHARACTERISTICS OF THE STRUCTURAL COMPOSITES INDUSTRY.

AS YOU CAN SEE, A 5 BILLION DOLLAR METAL SUBSTITUTION POTENTIAL

HAS BEEN IDENTIFIED WITH THE MAJOR END-USE APPLICATIONS BEING

AIRCRAFT/AEROSPACE, RECREATION, INDUSTRIAL, AND AUTOMOTIVE.

Over the next ten years, aerospace/aircraft will represent

APPROXIMATELY 50% OF THE TOTAL COMPOSITE BUSINESS. THEREFORE,

THIS IS THE PRIMARY END-USE AREA WHERE COMPOSITES WILL HAVE A

SIGNIFICANT IMPACT ON CRITICAL MATERIAL USAGE IN THE 80'S,

The overall industry has generally been characterized as having

HIGH TECHNOLOGY, HIGH VALUE ADDED PRODUCTS, AND HIGH CAPITAL

INTENSITY. The OBVIOUS IMPLICATION HERE IS THAT SEVERAL LARGE

CORPORATIONS WITH SUBSTANTIAL CAPITAL RESOURCES AND TECHNOLOGY

BASES WILL BECOME DOMINANT FACTORS IN THIS BUSINESS. THIS IS

AN IMPORTANT PARAMETER WHEN CONSIDERING CRITICAL MATERIAL

SUBSTITUTION.

Having described the general characteristics of composite

MATERIALS AS WELL AS THE NATURE AND CONDITION OF THE EMERGING

INDUSTRY, I'D NOW LIKE TO PRESENT AN OVERVIEW OF AEROSPACE

AND NON-AEROSPACE APPLICATIONS. THE OTHER TWO SPEAKERS THIS

MORNING WILL DESCRIBE IN MORE DETAIL THE POTENTIAL FOR COMPOSITE SUBSTITUTION IN THESE INDUSTRIES. FIRST, LET'S

EXAMINE COMPOSITES' UTILIZATION IN AIRCRAFT WHERE THE PRESENT

RAPID GROWTH IS OCCURRING.

P41-8
8

A MAJORITY OF THE DEVELOPING AIRCRAFT APPLICATIONS DO NOT

REQUIRE VERY HIGH TEMPERATURE PERFORMANCE AND HENCE CAN BE

SATISFIED WITH ORGANIC MATRIX COMPOSITES, HOWEVER, AS I'LL

ILLUSTRATE LATER IN DISCUSSING TYPICAL AIRCRAFT APPLICATIONS,

THE USE OF CRITICAL MATERIALS SUCH AS TITANIUM IN ENGINE

APPLICATIONS IS DECREASED PRINCIPALLY BY CASCADE EFFECTS

ASSOCIATED WITH DOWN SIZING OF THE OVERALL STRUCTURE INCLUDING

THE ENGINE, It'S NOTEWORTHY NONETHELESS, THAT EXTENSIVE EFFORTS

ARE BEING EXPENDED TO DEVELOP METAL MATRIX COMPOSITES FOR HIGH

TEMPERATURE APPLICATIONS, IN THIS NEXT SLIDE (FIGURE 7) ARE

LISTED THE TYPES OF SYSTEMS CURRENTLY UNDER DEVELOPMENT, As

CAN BE SEEN, CARBON, BORON, SILICON CARBIDE AND ALUMINA FIBERS

ARE BEING COMBINED WITH METALLIC MATRICES SUCH AS ALUMINUM AND

MAGNESIUM. TUNGSTEN IS ALSO OF INTEREST. THESE METAL MATRIX

FIBROUS COMPOSITES CAN DIRECTLY SUBSITUTE FOR CRITICAL METAL

STRUCTURES AND THUS ALLEVIATE PRESSURE ON AVAILABLE VOLUMES.

A SEPARATE EXAMPLE OF CRITICAL MATERIAL SUBSTITUTION IS THE

REPLACEMENT OF ALLOYS IN CERTAIN LOW THERMAL EXPANSION APPLICATIONS BY GY-70 GRAPHITE COMPOSITES.

The next slide (Figure 8) highlights, in general, the technical

AND ECONOMIC IMPACT OF ADVANCED COMPOSITES UTILIZATION IN

AIRCRAFT. The first point to be addressed is the significant

WEIGHT SAVINGS DEMONSTRATED WITH COMPOSITES. FOR COMMERCIAL

AIRCRAFT, THIS TRANSLATES DIRECTLY TO FUEL SAVINGS, LOWER

OPERATING COSTS AND INCREASED PROFITS, COMMERCIAL TRANSPORTS

P41-9
- 9

-

HAVE EXTREMELY HIGH LIFE TIME MILEAGES, E.G., 20-50MM MILES.

High mileage combined with reduced fuel consumption enables

REDUCTIONS IN LIFE-TIME OPERATING COSTS OF SEVERAL HUNDRED

DOLLARS PER POUND OF WEIGHT SAVED. FOR MILITARY AIRCRAFT,

THE WEIGHT SAVED TRANSLATES TO IMPROVED PERFORMANCE IN BOTH

MANEUVERABILITY AND RANGE. IN BOTH MILITARY AND COMMERCIAL

AIRCRAFT, SIGNIFICANT REDUCTIONS IN MANUFACTURING COSTS ARE

ACHIEVED THROUGH PARTS CONSOLIDATION, WHICH IN TURN LEADS TO

FURTHER WEIGHT REDUCTIONS THROUGH THE ELIMINATION OF FASTENERS.

In the next slide (Figure 9), is shown the increase in fuel

PRICES EXPERIENCED BY THE COMMERCIAL TRANSPORT INDUSTRY IN THE

1973 TO 1980 TIME FRAME. MORE THAN A SEVEN-FOLD RISE IN PRICE

HAS OCCURRED. AT THE CURRENT TIME, IN EXCESS OF 50% OF THE

DIRECT OPERATING COST OF COMMERCIAL CARRIERS IS DIRECTLY

ATTRIBUTED TO FUEL CONSUMPTION. THIS CLEARLY ACCOUNTS FOR

INDUSTRY INTEREST IN THE WEIGHT REDUCTION AND FUEL CONSERVATION OFFERED BY ADVANCED COMPOSITES.

In recognition of the potential economies and conservation

WHICH COULD BE REALIZED BY WEIGHT REDUCTION OF COMMERCIAL

TRANSPORTS, NASA HAS FUNDED A PART OF THE AIRCRAFT ENERGY

Efficiency or ACEE Program in which millions of dollars have

BEEN SPENT TO STIMULATE FUEL-SAVING DEVELOPMENTS. THE NEXT

slide (Figure 10) illustrates the effect of reduction in

P41-10
- 10 -

AIRCRAFT WEIGHT ON OPERATING COSTS. BOTH IMPROVEMENTS IN DIRECT

OPERATING COSTS AND IN FLEET LIFETIME OPERATING COSTS ARE SHOWN.

It's important to note that utilization of composites in

EMPENNAGE AND SECONDARY STRUCTURES HAS A REAL, BUT MINOR, EFFECT

IN REDUCING OPERATING EXPENSES BY SLIGHTLY LESS THAN 1% BECAUSE

ONLY 3% OF THE STRUCTURE WEIGHT IS INVOLVED IN THESE APPLICATIONS.

However, when primary structures such as wing and fuselage

ELEMENTS ARE SUBJECT TO MATERIAL SUBSTITUTION, THE OPERATING

COSTS ARE REDUCIBLE BY MORE THAN 6%. AS ONE BECOMES EVEN MORE

CONFIDENT IN THE PERFORMANCE AND RELIABILITY OF COMPOSITES,

THEN THESE OPERATING COST REDUCTIONS CAN APPROACH OR EVEN

EXCEED 10%. IN THIS CASE, SUBSTITUTION FOR METAL IN APPROXIMATELY 50% OF THE STRUCTURE IS PROJECTED. IT MUST, OF COURSE,

BE POINTED OUT THAT A PORTION OF THE REPLACED METAL CAN BE

TITANIUM WHICH IS ON THE CRITICAL MATERIALS LIST.

The weight and fuel savings which can be achieved by materials

SUBSTITUTION ARE NOT SIMPLY STATED. SINCE THERE ARE CASCADE

EFFECTS INVOLVED, IT'S WORTHWHILE EXAMINING THE EFFECTS OF

SUBSTITUTION ONLY AND THEN SUBSTITUTION ACCOMPANIED BY DOWNSIZING OF THE TRANSPORT. IN THE NEXT SLIDE (FIGURE 11) ARE

SHOWN THE GROSS TAKE-OFF WEIGHTS FOR THE ALL-METAL PLANE WHEREIN

THE DIRECT EMPTY WEIGHT IS SEPARATELY IDENTIFIED. CHANGES IN

THE STRUCTURAL WEIGHT WITHOUT CORRESPONDING DOWN-SIZE OF THE

CRAFT LEADS TO A FUEL SAVINGS OF APPROXIMATELY 6%. HOWEVER,

AS NOTED ON THE FAR RIGHT WHEN CASCADING EFFECTS ARE BROUGHT

INTO PLAY, THEN TOTAL FUEL SAVINGS ARE ENHANCED TO THE 12 TO

15% LEVEL.

P41-11
- 11 -

While it's fair to speak in generalities, a few specific

EXAMPLES PUBLICIZED BY BOEING ARE USEFUL TO ILLUSTRATE THE

SOURCE OF WEIGHT REDUCTIONS WITH SUBSTITUTION OF COMPOSITES.

In the next slide (Figure 12) is shown the reduction in number

OF ACTUAL PARTS AND IN NUMBER OF FASTENERS WHICH ACCOMPANY

PARTS CONSOLIDATION FOR 727, 737 AND 747 COMPONENTS. THE

NUMBER OF PARTS IS REDUCED BY 40 TO 55% WITH THE CORRESPONDING ELIMINATION OF APPROXIMATELY 60% OF THE FASTENERS AND

TOTAL COMPONENT WEIGHT REDUCTIONS OF 23 TO 26%. THESE

FIGURES TYPIFY THE WEIGHT SAVINGS AND THEIR ORIGINS WHICH

HAVE BEEN ACHIEVED IN THE NASA-ACEE PROGRAM.

The next two slides illustrate the projected expansion of

STRUCTURAL COMPOSITES UTILIZATION ON COMMERCIAL AIRCRAFT.

First, in the next slide (Figure 13) are shown the materials

PLANNED TO BE USED ON THE 757 AND 767 SHIPS. FOR REFERENCE

PURPOSES, THE 747 CONTAINS APPROXIMATELY 1% FIBERGLASS

COMPOSITE WHILE THE 757 AND 767 SHOW 3% COMPOSITE STRUCTURES

OF WHICH 2.5% ARE CARBON FIBER AND/OR KEVLAR REINFORCED

MATERIAL. WHILE MOST OF THE CURRENT USAGE IS IN SECONDARY

STRUCTURES, FAR MORE EXTENSIVE COMPOSITES UTILIZATION IS

FORECAST FOR THE 1990 # S. THIS IS DEPICTED IN THE NEXT SLIDE

(Figure 14) which shows 7 to 32% of the structural weight in

composites. However, because of the confidence and reliability

CURRENTLY BEING ESTABLISHED, SEVERAL COMMERCIAL AIRFRAME

MANUFACTURERS ARE NOW PROJECTING THAT COMPOSITES WILL

P41-12
- 12 -

CONSTITUTE MORE THAN 50% OF THE STRUCTURE OF COMMERCIAL TRANSPORTS BY THE EARLY 1990 # S.

TO APPRECIATE THE TOTAL POTENTIAL FOR COMPOSITES IN AIRFRAMES,

I'VE USED A SCHEMATIC SUCH AS SHOWN IN THE NEXT SLIDE (FIGURE 15),

Here the steady, but incremental, increases in specific strength

OF DEVELOPING MATERIALS FROM THE 1930'S FORWARD ARE SHOWN. NEW

ALUMINUM ALLOYS AND POWDERED METALS SHOW THE SAME CONTINUED

INCREMENTAL INCREASES THROUGH THE YEAR 2000, IT IS ONLY WITH

THE INTRODUCTION, DEMONSTRATION AND UTILIZATION OF HIGH PERFORMANCE CARBON FIBER COMPOSITES THAT SIGNIFICANT STEP-CHANGES IN

PERFORMANCE CAN BE PROJECTED.

While the majority of the aircraft utilization is based on

COMMERCIAL TRANSPORTS, IT MUST BE RECOGNIZED THAT MILITARY

AND CIVILIAN UTILIZATION OF CARBON FIBER COMPOSITES WILL MORE

THAN DOUBLE THE USAGE QUANTITIES I'VE DISCUSSED, AS POINTED

OUT EARLIER, IN ADDITION TO PERFORMANCE, A DRIVING FORCE FOR

COMPOSITE SUBSTITUTION OF METALS IS WEIGHT REDUCTION WITH

RESULTING FUEL ECONOMY AND/OR IMPROVED RANGE PROVIDING THE

DEPENDENT BENEFITS. WHATEVER THE DRIVING CAUSE FOR WEIGHT

REDUCTION VIA MATERIAL SUBSTITUTION, THE POSITIVE EFFECT OF

CONSERVATION OF CRITICAL MATERIALS SUCH AS TITANIUM REMAINS

THE SAME. The LOWER THE USAGE OF CRITICAL METALS, THE LESS

CONSTRAINED IS THE SUPPLY OF SUCH METALS FOR THE CRITICAL

APPLICATIONS WHERE SUBSTITUTION IS NOT A VIABLE ALTERNATIVE.

P41-13
- 13 -

The automotive/industrial market, as shown on the next slide

(Figure 16 ), is the next target for structural composite

MATERIALS, THOUGH MANY DEMONSTRATION ARTICLES HAVE BEEN BUILT

OVER THE PAST FEW YEARS, VERY FEW HAVE REACHED EVEN THE LIMITED

PRODUCTION PHASE. BY THE WAY, THIS DOES NOT INCLUDE THE

CHOPPED GLASS-POLYESTER SHEET MOLDING COMPOUNDS WHICH HAVE

FOUND WIDE USAGE AS ZINC REPLACEMENT IN NON-STRUCTURAL APPLICATIONS SUCH AS AUTO GRILL OPENING PANELS AND HEADLAMP COVERS,

Chevrolet is now using a glass epoxy leaf spring in structural

USAGE IN THE 1981 CORVETTE. NOTE THAT THE SPRING STEEL IT

REPLACES CONTAINS SMALL QUANTITIES OF CHROMIUM, ONE OF THE

CRITICAL METALS, CONTINUING WITH AUTOMOTIVE APPLICATIONS,

THOUSANDS OF COMPOSITE DRIVESHAFTS HAVE BEEN PROTOTYPED FOR

TEST AND EVALUATION AT ALL MAJOR AUTOMOTIVE COMPANIES, AND

WITHIN A FEW YEARS, SUBSTANTIAL PRODUCTION QUANTITIES ARE

expected, Longer term, metal matrix composites are candidates

FOR HIGH TEMPERATURE ENGINE COMPONENTS,

In reviewing non-automotive areas, the chemical industry

UTILIZES SUBSTANTIAL QUANTITIES OF STAINLESS STEEL IN PIPING

AND VALVES BECAUSE OF THE CORROSION PROBLEMS WITH ORDINARY

STEELS AND COMPOSITE REPLACEMENT POSSIBILITIES ARE BEING

ACTIVELY EVALUATED IN THIS INDUSTRY. FOR INSTANCE, THERE'S

NOW A COMMERCIALLY AVAILABLE BALL VALVE MADE FROM CHOPPED CARBON

FIBER AND PPS (POLYPHENYLENE SULFIDE), A HIGH TEMPERATURE

THERMOPLASTIC.

P41-14
14

The marine industry is yet another area where composite materials

REPLACEMENT IS OCCURRING, IN THIS CASE, FOR STAINLESS STEELS THAT

ARE RESISTANT TO SALT WATER CORROSION. HERE, COMPOSITES THAT

CONTAIN GLASS, CARBON, AND KEVLAR FIBERS ARE FINDING INCREASED

USAGE IN TUBING, FITTINGS AND TORQUE SHAFTS.

It's important to recognize that though the composites activity

IN THESE INDUSTRIES IS NOT GREAT AT PRESENT, THERE IS CONSTANT

ECONOMIC PRESSURE THAT WILL STIMULATE MATERIALS INNOVATION, AND,

IN YEARS TO COME, SUBSTANTIAL METAL REPLACEMENT WILL TAKE PLACE.

In summary. I'd like to point out that two methods for alleviating THE DEMAND ON CRITICAL METALS BY COMPOSITE SUBSTITUTION

HAVE BEEN IDENTIFIED. THE FIRST APPROACH IS THE DIRECT SUBSTITUTION OF METAL MATRIX COMPOSITES FOR METALS IN HOT ENVIRONMENTS;

THIS PERMITS REDUCTION IN THE USAGE OF CRITICAL METALS SUCH AS

TITANIUM AND BERYLLIUM. IN THE SECOND APPROACH, THE STRUCTURAL

WEIGHT OF A TRANSPORT VEHICLE, SUCH AS AN AIRFRAME, IS DIRECTLY

REDUCED BY SUBSTITUTION OF ORGANIC MATRIX COMPOSITES FOR

ALUMINUM, AND, ALTHOUGH ALUMINUM ITSELF IS NOT A CRITICAL

MATERIAL, A SECONDARY DOWN-SIZING OF THE ENGINE IS NOW PERMITTED

AND THIS REDUCES THE QUANTITY OF TITANIUM REQUIRED FRO THE

SMALLER ENGINE. SPECIFIC ILLUSTRATIONS OF SUCH COMPOSITE SUBSTITUTION FOR METALS IN BOTH AEROSPACE AND NON-AEROSPACE

APPLICATIONS WILL BE GIVEN BY THE TWO SPEAKERS WHO FOLLOW ME

THIS MORNING.

P41-15
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P41-22
P41-23

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P41-24
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P41-30

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P41-31
ROLE OF COMPOSITES IN SUBSTITUTION, CONSERVATION AND

DISPLACEMENT OF MATERIALS AND POTENTIAL FOR SUBSTITUTION

IN MILITARY AND COMMERCIAL AEROSPACE

Richard N. Hadcock

Grumman Aerospace Coro.

P42
WORKSHOP ON CONSERVATION AND

SUBSTITUTION TECHNOLOGY FOR CRITICAL MATERIALS

VANDERBILT UNIVERSITY

NASHVILLE, TENNESSEE

15-17 JUNE 1981

SPONSORED BY

U S. DEPT OF COMMERCE/NATIONAL BUREAU OF STANDARDS

U.S. DEPT OF INTERIOR/BUREAU OF MINES

ROLE OF COMPOSITES IN

SUBSTITUTION, CONSERVATION,

AND DISPLACEMENT OF MATERIALS

AND POTENTIAL FOR SUBSTITUTION

IN MILITARY AND COMMERCIAL AEROSPACE

RICHARD N. HADCOCK

GRUMMAN AEROSPACE CORPORATION —RUMMAN

P42-1
JUNE 1981 The Role of Composites in Substitution

and

Potential for Substitution in

Military and Commercial Aerospace*

R. N. Hadcock

Grumman Aerospace Corporation, Bcthpage, N. Y.

Abstract

This paper discusses aerospace structural materials, the development of structural composite materials technology, and their properties and current and future applications.

Metallic and composite material prices, energy requirements, and availability are addressed. The difference between metal and composite part fabrication is described.

In conclusion, an assessment is made of the

I. Introduction

Advanced composites structures and materials

technologies have been developing steadily during the past 20 years. The technology has reached a level of maturity which led to its use on stabilizers for all new U.S. fighter aircraft since 1970 (F-14, F-15,

F-16, YF-17, F-18), and these parts are generally

giving trouble-free service. Fighter wing covers

(F-18) and the covers and substructure of a V/STOL

attack aircraft (AV-8B) are currently being made

from graphite/epoxy advanced composite material;

these will be entering service in the next year or so. The next generation of commercial aircraft (Boeing

757 and 767) will extensively use advanced composites for such secondary structural parts as ailerons, elevators, rudders, and spoilers. There is

still a need for additional development work on hightemperature composite systems, manufacturing technology, the design-manufacturing interface, and

fatigue and fracture. However, the technology's current level of maturity makes it a strong candidate

for a large proportion of the airframes of future

military and commercial aircraft.

II. Material Application

Since new structures and material development

takes from 20 to 30 years from conception to widepotential for material substitution.

spread application, it is highly improbable that any

technologies other than those either currently available or in the advanced development cycle will be sufficiently mature to be considered for application in the next generation of military or commercial

aircraft.

Since the beginning of the century, many

different materials and types of construction have

been used for airframes. Wilbur and Orville Wright

used wood, wire, and fabric for their Flyer in 1903. This was the standard type of construction until the middle 1920's, when metal framing began to replace

wood. Aluminum stressed-skin had become an accepted form of construction by the early thirties,

about 20 years after the first flight of Hans

Reissner's all-metal monoplane in 1912. Magnesium

airframes came and went (primarily because of major

corrosion problems) during the thirties and forties, as did stainless steel (primarily because of weight

and manufacturing problems) during the forties and

fifties. Material availability has often driven the design in the past. During WW II, shortages of aluminum led to the all-wood de Havilland Mosquito in Britain. It also led to the use of wooden wings in conjunction with aluminum fuselages for the

Messerschmitt Me 163. In their time, both the Mosquito bomber and Me 163 fighter had outstanding

performance characteristics.

‘Presented at the Workshop on Conservation and Substitution Technology for Critical Materials, sponsored by the National Bureau of Standards of the U.S. Dept, of Commerce and the Bureau of Mines of the U.S. Dept, of Interior on June 15-17, 1981, at Vanderbilt University, Nashville, Tennessee.

P42-2
ADV FIGHTER Titanium had become an accepted material for hightemperature applications by the middle fifties. Titanium

utilization reached a peak during the 1 9 6 0

' s with the all- titanium SR-71/YF-12; titanium is still extensively used

for the wings and carry-through structure of such aircraft as the F-14 and F-15. New process developments

such as superplastic forming in conjunction with diffusion bonding and hot isostatic pressing of titanium

powders are probable applications of new titanium

technology to future tactical aircraft. By the late sixties, organic-matrix advanced composites had become sufficiently developed for production

of the covers of F-14 horizontal stabilizers. Production

applications were extended during the seventies to vertical stabilizers and rudders (F-15, F- 16), wing

covers (F-18), and, finally, to the complete wing,

stabilizer, and part of the forward fuselage (AV-8B).

Metal-matrix composites, in the form of boron/aluminum, Borsic/aluminum, boron carbidecoated boron/titanium, and silicon carbide/titanium

are currently being developed and could become

effective for limited selective reinforcement or replacement of existing metal airframe structures,

but only if their costs can be reduced significantly.

Boron/aluminum composites are being used for tubular support struts in the keel of the fuselage of the Space Shuttle. Metal matrix composites are likely to be extensively used for space applications due to their excellent thermal stability properties in combination with high specific stiffness. Aerospace

materials application during the twentieth century is depicted in Fig. 1, and the full 25-year advanced

composite development cycle is illustrated in Fig. 2.

Fig. 1 Aerospace Materials Application

ADVANCED

COMPOSITE

MATERIALS. % STRUCTURE

WEIGHT

R81-0990-006(T) Fig. 2 Advanced Compoiste Implementation

(Aircraft)

Figure 3 provides a comparison between

advanced composite and metallic specific tensile strengths. Here, the strengths of the composites

used are realistic working stress levels for multidirectional laminates as would be used for wing or

stabilizer covers. Figure 3 shows that composites

2.0

SPECIFIC

1.5 TENSILE STRENGTH, 1.0

F

{ /p 106

IN.

.51.

. Gr/Ep NO HOLES

Gr/Ep 5/16 HOLES. B/Ep NO HOLES

~TGLASS/EPOXY

KEVLAR/EPOXV GLASS/PQLYESTER SPRUCE

1930 1940 1950 I960 1970 1980 1990 2000

R81-0990-007ITI YE A R 0 F I NTRO D U CTION Fig. 3 Specific Working Tensile Strengths

of Materials

are very hole-sensitive relative to metals. However,

this penalty is offset by far less sensitivity to tension fatigue. Their effectiveness in compression

applications is shown in Fig. 4 where the low density

kg/m2 LB/IN.2 m IN.

Fig. 4 Weight of Long Compression Panels

P42-3
significantly reduces panel weight but, in contrast to metals, compression fatigue now becomes a design

consideration

.

Materials are available or currently under

development which could effect significant weight

reductions on future aircraft. It is very probable

that all future high-performance aircraft, whether

military or commercial, will be made from a mix of aluminum, titanium, steels, and advanced composites. The use of advanced composites is expected

to increase with time. Figure 5 shows the material

mix of AV8B V/STOL aircraft which is just entering

production.

STRUCTURAL

WEIGHT

GRAPHITE/EPOXY 26.3%

R81-0990-009(T)

Fig. 5 AV-8B Composite Application

A conceptual subsonic Navy V/STOL aircraft of the 1990's is shown in Fig. 6. Composites would

probably account for more than 60% of the weight of

this Airborne Early Warning (AEW) aircraft.

CH) EPOXY MATRIX COMPOSITES

Fig. 6 Material Distribution - Subsonic V/STOL

AEW Aircraft

Composites secondary structure on the new

Boeing 757 commercial aircraft is shown in Fig. 7. Total weight is 1900 lb of a mixture of graphite and

Kevlar/epoxy . The total weight of composites on the larger Boeing 767 is 2860 lb.

• GRAPHITE/KEVLAR EPOXY

• 1900 LB TOTAL WEIGHT

MAIN LANDING GEAR DOORS

RUDDER

ELEVATORS

SPOILERS AILERONS

WING TO BODY FAIRINGS ENGINE STRUT FAIRINGS FLAP TRACK FAIRINGS NACELLE COMPONENTS

(TOTAL WEIGHT OF SIMILAR PARTS ON BOING 767 IS 2860 LB)

Rfll -09 90-01 1(T) Fig. 7 Next Generation Commercial Aircraft

Advanced Composite Material Utilization

The use of composites in these aircraft

applications will result in lower procurement and

operating costs. The weight savings are directly

transformed into improved performance and fuel savings or, in the case of military aircraft, into smaller, lighter, and less expensive aircraft capable

of the same mission performance.

A projection of the flyaway weight of advanced

composite aircraft and helicopter structure is shown

in Fig. 8. Composites are projected to account for at least 1 million lb of structure by 1988, an order of magnitude increase in eight years. It can be seen SECONDARY

ADVANCED

COMPOSITE AIRFRAME

PRODUCTION, KLB/ YR FLYAWAY WT

R81-0990-012(T) Fig. 8 U.S. Advanced Composite Airframe

Production 1980-1990 (Commercial & Military Aircraft & Helicopters)

'80 '81 '82'83'84'85'86'87’88'89 CALENDAR YEAR

P42-4
from the figure that only 25% of the material will be

used for primary structure, mainly in the form of wing and stabilizer covers of military nircroft. The

major use of these materials will be for secondary

structure of commercial aircraft.

Total aerospace material consumption estimates

to 1990 are shown in Fig. 9. In addition to aluminum,

steel, and titanium, consumption estimates are shown

for graphite, glass, and Kevlar fiber. It should be

noted that the glass and Kevlar fiber composites are and will continue to be utilized for secondary air- frame structures and filament-wound rocket motor

cases. Boron, silicon carbide, and alumina fibers

have not been included in the chart since they are

projected to be used only in small quantities.

Although the consumption of both graphite and Kevlar

fiber is projected to increase by an order of magnitude, the proportion of fiber weight increases only

from 8.5% in 1980 to 11% in 1990.

Fig. 9 U.S. Aerospace Material Consumption

Estimates

Three factors are primarily responsible for inhibiting widespread substitution of composites for metals. These are:

• Material costs

• Manufacturing facilities costs

• Non-recurring costs associated with design,

development, tooling, and certification of replacement parts where composites are substituted for metals. Flyaway costs of primary structural materials arc shown in Fig. 10. The graphite/epoxy material

has a flyuway cost four times higher than aluminum

( $60 /lb vs $15/lb). Allowing for weight savings of

2>j% to 30%, which have been typically demonstrated

using graphite/epoxy, material cost of the composite

FLY

BUY TO FLY AWAY

P RICE, RATIO COST MATERIAL $/LB (TYPICAL) S/LB

CONVENTIONAL ALUMINUM 1.80-2.2 8.0 15

14 TECHNOLOGY STEEL (PH STAINLESS) 2.70 5.0 TITANIUM 16-31 6.0 100

GRAPHITE/EPOXY TAPE 38-55 1.3 60 GRAPHITE/EPOXY CLOTH 70-80 2.0 150 ADVANCED

TECHNOLOGY BORON/EPOXY TAPE 242 1.25 300 TITANIUM NEAR NET SHAPES 2540 1.5 53 TITANIUM-SPF/DB 16 31 2.0 50

b/b4 C/TITANIUM 600-1000 U« 1000

•WHEN USED AS SELECTIVE REINFORCEMENT

R81-0990-014(T> Fig. 10 Aerospace Material Prices Fall 1980

part is still effectively twice as high as its aluminum

counterpart. This recurring cost difference must be

offset by lower manufacturing costs or by lower oper

ating costs if the composite part is to be competitive.

This situation could change if there is again a major escalation in the price of energy. Energy

requirements for conventional metals fabrication and

advanced composites and titanium fabrication are compared in Fig. 11. As can be seen, the energy

associated with composites fabrication is only 15% of that needed for aluminum.

ENERGY (10 3 BTU/FLYAWAY LB) RAW MATERIAL

BUY-TO FLY

RATIO CONVERSION

MATERIAL BILLET (TYP) SUBTOTAL (TYP) TOTAL

CONVENTIONAL ALUMINUM 108 8.0 864 64 928 TECHNOLOGY

STEEL 19 5.0 95 260 355

TITANIUM 185 6.0 1110 258 1368 ADVANCED COMPOSITES 40 1.5 60 78 138 TECHNOLOGY

TITANIUM-SPF/DB 185 2.0 370 160 430

R8 1 -0990 -00 2 (T)

Fig. 11 Energy Requirements

P42-5
The situation could also change if the 1979 aluminum and titanium sheet, plate, extrusion, and

forging lead times of 24 to 35 months recur. Lead

time for some graphite/epoxy materials have lately

risen from two or three months to twelve months, but

this situation is likely to be improved during the coming year. Typical historical data on material

lead-times is shown in Fig. 12.

R81-0990-015(T) Fig. 12 Aerospace Material Leadtimes

Sheet and Plate

The availability of indigenous sources of both

base materials and final material form is of concern. Although Kevlar and glass fiber is 100% available from

indigenous sources, the polyacrylonitrile (PAN)

precursor, which is used as a base for the structural

graphite fiber, is currently 98% imported from Japan

and the United Kingdom. In addition, almost 55% of the graphite fiber is currently imported from Japan.

The situation will be improved as the new

facilities in South Carolina come on line, but it is very likely that imported PAN precursor and fiber

will account for the majority of U.S. graphite fiber sources throughout the 1980's. In comparison,

almost 90% of aluminum production is indigenous, even

though imported Bauxite accounts for 92% of the base

mineral (Fig. 13).

III. Manufacturing Considerations

The processes associated with conventional

metal and composite part fabrication are totally

different. Incoming metal, in the form of sheet,

plate, extrusion, or forgings, is inspected and stored

in a warehouse. The material is rough cut to size,

packaged with operation sheets, machined, formed,

trimmed, cleaned, heat treated, and inspected prior

to assembly. The parts are then assembled by bolting, riveting, welding, or adhesive bonding to form

components. A significant proportion of the material

is removed during the machining operations (Fig. 10 shows typical buy-to-fly ratios).

BASE MINERALS & MATERIALS

PANPRE- BAUXITE ILMENITE IRON

AEROSPACE STRUCTURAL MATERIALS

GRAPHITE KEVLAR

FEB. 1979 "AVAILABILITY OF STRATEGIC MATERIALS" AV. WEEK

MAY 5, 1980 "DEFENSE SCIENCE BOARD URGES MULTIYEAR CONTRACTS"

AV. WEEK DEC 1, 1980

R81-0990-016(T>

Fig. 13 U.S. Aerospace Structural Material Availability (1980) Indigenous/imported

P42-6
Typical large, two-spindle, three-axis aluminum

skin mills are shown in Fig. 14. More complex shaoes

are machined using five-axis numerically controlled

machines.

. .

II II In R81-0990-021(T) Fig. 14 Aluminum Skin Mill

Entirely different processes and facilities are

utilized for fabrication of organic matrix composite

parts. The structural composite material is received

in the form of preimpregnated tape or broadgoods in refrigerated containers. It is then inspected visually

and destructive test specimens are fabricated to determine that physical and mechanical properties meet the material specification. The material is stored in a refrigerator since a room temperature

environment causes the resin to advance and limits out-time.

Part fabrication consists of trimming individual

plies to shape, stacking and debulking the plies on

the tool, and finally autoclave curing under a combination of temperature and pressure. The ply

trimming and layup (stacking) operations should be

performed in a humidity /temperature controlled clean

Fig. 15 Milledgeville , Georgia, Composites Facility

INTEGRATED

LAMINATING CENTER

COMPUTERIZED BROADGOODS DISPENSER STITCHING MODULE

• RAPID LAYUP. TRIMMING & • GENTLE CONTOURS

INSPECTION • COMPLEX FUSELAGE SHAPES

• TAPE & BROADGOODS • AUTOCLAVE LOADING TIE-IN

R8J-0990-020(T) Fig. 16 Material and Manufacturing Development

Automated Integrated Manufacturing System

(AIMS) for Advanced Composites

room and accomplished within a specified time period,

usually one week. The cured parts are trimmed to

final size and inspected. Figure 15 shows the Grumman composite facility. Figure 16 shows

elements of an automated integrated manufacturing

system for fabrication of complex composite parts

which has lately been developed.

IV. Conclusions

Composites will constitute a larger proportion of the airframe weight of future military and commercial

aircraft. The resulting weight savings will result in significant reductions in life cycle costs. However,

widespread substitution of composites for aluminum

and titanium in existing structural parts is unlikely

due to the costs of redesign, development, tooling,

and certification. Even so, the aerospace utilization of structural composites will increase by at least an order of magnitude by the end of the decade. This

will require major investment in new manufacturing

facilities dedicated to automated fabrication of complex composite parts.

Bibliography

R. N. Hadcock, "Introduction of New SDM Technology into Production Systems," AIAA paper 79-071R, Journal of Aircraft, Vol.

17, No. 9, September 1980.

R. N. Hadcock, "The Introduction of Advanced Metallic and Composite Structures into Future Tactical Aircraft," Tactical Aircraft Research and Technology Conference, NASA Langley Research Center, Hampton, VA, October 1980. (NASA CP-2162

Vol. II.)

J. D. Morgan, Jr., "Minerals Availability - The Mineral Position of the United States," American Mining Congress Annual Meeting, Los Angeles, CA, September 1979.

"Seminar on Critical /Strategic Metals Status," Air Force Wright

Aeronautical Laboratories, Materials Laboratory, Dayton, OH,

February 1979.

D. E. Fink, "Technical Survey - Availability of Strategic Materials," Aviation Week and Space Technology, May 5, 1980.

Richard G. O'Lone, "Aeronautical Engineering Industry Tackles Composites Challenge," Aviation Week and Space Technology,

September 15, 1980.

P42-7
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P42-8

GRUMMAN

AEROSPACE

CORP
AIRCRAFT

MATERIALS

APPLICATION ooo

CMo

00

CDo

IDo>oao

CN

CTJ Oo

O)

P42-9

YEAR
ADVANCED

COMPOSITE

IMPLEMENTATION

(AIRCRAFT)

co<

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1

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D

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P42-10

1950

1960

1970

1980

1990

2000

FISCAL

YEAR
SPECIFIC

WORKING

TENSILE

STRENGTHS

OF

MATERIALS 2OHODQOXK2

LUOX<

LU>

CO

P42-11
WEIGHT

OF

LONG

COMPRESSION

PANELS

CMz

CM

o> H

X

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LUg -S

2

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Q.

P42-12

STRUCTURAL

INDEX

Nx/b
AV-8B

COMPOSITE

APPLICATION

P42-13

5,006

LBS

OF

STRUCTURE

1

,31

7

LBS

OF

GRAPHITE/EPOXY
MATERIAL

DISTRIBUTION—

SUBSONIC

V/STOL

AEW

AIRCRAFT

P42-14
U.S.

ADVANCED

COMPOSITE

AIRFRAME

PRODUCTION

1

980-1

990

(COMMERCIAL

&

MILITARY

AIRCRAFT

&

HELICOPTERS)

co

t—

x

tn

I *

P42-15

CALENDAR

YEAR
HTM

LL<

£CQ

cc oH<NHD

<<

LU ULi H< 8 m

zt

2o

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aco

uj o

Og

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CO

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CO

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P42-16
U.s.

AEROSPACE

MATERIAL

CONSUMPTION

ESTIMATES

<r<

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cc<

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z

LU

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UV3A/91 SNOmilAI - NOIldlAinSNOO

P42-17
TOTAL

U.S.

AIRCRAFT

PRODUCTION

P42-18
AEROSPACE

MATERIAL

PRICES

1981 >s co

CQ

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a o < O

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a.

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1- < 1-

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P42-19
ENERGY

REQUIREMENTS

«J< CO CO OS CQ

O

Li CM CO CO CO CO o

05 CO CO

H Zo

to

—

£3

0£ a. UJ > 64 o

CO

00in 78 o

CO > t CM CM p° Z > o < a §<>J

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5.0 6.0 in2.0 < D

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18

R o H _J 2 O ^ o

uj 2 5 z > X < X 2 o > a O uj Q uj O H ^ hP42-20
AEROSPACE

MATERIAL

LEADTIMES

-

SHEET

AND

PLATE

a

uj

m

-oc

H

LU <

as;-

SobI so

I- X

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UJ I UJ o

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P42-21

YEAR
U.S.

AEROSPACE

STRUCTURAL

MATERIAL

AVAILABILITY

(1980)

INDIGENOUS^MPORTED

CO<

UJ

III UJH

C/3 <

cc3

I-Q3

C£

H*

CO

UJO<a. C/3 O

cc

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CO

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P42-22

“AVAILABILITY

OF

STRATEGIC

MATERIALS”

AV.

WEEK

MAY

5,

1980

“DEFENSE

SCIENCE

BOARD

URGES

MULTIYEAR

CONTRACTS”

AV.

WEEK

DEC

1,

1980
ALUMINUM

SKIN

MILL

P42-23
MILLEDGEVILLE,

GEORGIA,

COMPOSITES

FACILITY
MATERIAL

AND

MANUFACTURING

DEVELOPMENT

AUTOMATED

INTEGRATED

MANUFACTURING

SYSTEM

(AIMS)

FOR

ADVANCED

COMPOSITES

r'-

P42-25
MANUFACTURING

CONSIDERATIONS

a

P42-26
SUMMARY

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UU _| m < O 5 ee £

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UJ

v

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Sfjhu. > ~ D u. O§o<

cr>

P42-27
POTENTIAL FOR SUBSTITUTION IN ALL USES

OTHER THAN AIRCRAFT/AEROSPACE

John P, Riggs

Celanese Corp.

P43
THE ROLE OF COMPOSITES IN

SUBSTITUTION, CONSERVATION, AND DISPLACEMENT

OF CRITICAL MATERIALS:

POTENTIAL FOR COMPOSITES SUBSTITUTION

IN ALL USES OTHER THAN

aircraft/aerospace

DR. JOHN P. RIGGS

TECHNICAL DIRECTOR, STRUCTURAL COMPOSITES

CELANESE CORPORATION

PRESENTED AT

THE WORKSHOP ON CONSERVATION AND SUBSTITUTION

TECHNOLOGY FOR CRITICAL MATERIALS

VANDERBILT UNIVERSITY

NASHVILLE, TENNESSEE

JUNE 17, 1981

P43-1
WORKSHOP ON CONSERVATON AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS

POTENTIAL FOR COMPOSITES SUBSTITUTION IN ALL USES

OTHER THAN AIRCRAFT/AEROSPACE

J. P. Riggs

Celanese Corporation

(June 17, 1981)

My objective in this overview is to provide some perspective on the utilization

of composite materials in structural applications other than those in aircraft/

aerospace end uses; and to tie together some of the points previously made.

Specifically, these uses encompass recreational, marine, general industrial,

and transportation market segments--wi th principal emphasis being on the latter

two. As indicated in the first slide, these objectives include the following:

Provision of a broad outline of the types of nonaerospace applications and the

reasons for use of high performance composites (in this instance focused in the

main on carbon fiber reinforced organic matrices); delineation of the different

constraints on the technical and economic impact of high performance composites

in industrial and automotive applications versus those in aerospace; and finally,

key needs and issues needing resolution for full realization of the potential

of structural composite materials in these types of applications.

In nonaerospace areas, broad, direct impact on utilization of the most

critical materials is minimal, although there can be very significant

influence on the use of various alloys of aluminum and steel, and

P43-2
potentially magnesium. In addi tion--as should become evident--the materials

form and manufacturing technology being developed to support cost effective

application in nonaerospace sectors may ultimately spin back to provide broadened

utilization at lower cost in that sector.

As has been indicated by the previous speakers, over the last decade, fiber

reinforced composites have emerged as a new class of structural materials,

offering attractive-- indeed uni que--combi nations of static and dynamic properties

at significantly reduced weight and overall energy consumption (from component

manufacture through life cycle costs in end-use applications). Also, because

of the anisotropic nature of the systems, the variety of reinforcements and

matrix materials, and the state of current computer assisted design techniques,

they provide an unparalleled opportunity for tailor-making such materials for

a broad spectrum of applications. The development of higher performance

(compared to glass) rei nforcements such as carbon fiber, aramids, and silicon

carbide have resulted in composite systems with performance character!’ sties

exceeding those of metals, and the use of glass in high loadings as a chopped

and/or continuous reinforcement is developing rapidly expanding uses for this

material in structural applications. The combination of end-use incentives

and reinforcement materials availability is also driving the development of

much improved resin matrix systems, with the latter contributing a combination

of strain, impact, and environmental durability characteristics that will

permit composite utilization in areas as demanding as primary aircraft structure.

All of this is being built on a foundation of over forty years' experience

with fiber glass reinforced materials.

Chopped glass or woven fiber glass mats, impregnated with resin, have been used

for many years in the manufacture of fiberglass boats and other recreational

P43-3
vehicles, and continuous filament glass wound fishing rods have also been

common for some time. Utilization of composite materials in these types of

uses have been significantly extended through the use of graphite and aramid

(Kevlar ) reinforcements; these provide not only lighter weight, but increased

sensitivity, responsiveness, and damping characteristics in fishing rods and

various racquets; boats using carbon fiber masts--and other rigging--are

repeatedly winning major competitions. Regardless of the various therapeutic

claims made for these applications, the technical merits are generally sound,

and provide an interesting use of a combination of composite characteristics;

but, however, with negligible effect on metals usage.

By far, the most dramatic potential for the use of these materials in nonaerospace areas, and for the large-scale replacement of metals, lies in automotive

and industrial applications. To put this in some perspective, in 1980, on the

order of 700 million pounds of fiber glass reinforced plastics were used in

the transportation industry--and this is projected to grow to 1 billion pounds

in the next several years--essential ly all in nonstructural applications, and

the potential for use in structural areas--with a variety of reinforcements--

could add very substantially to these numbers. The basic incentives and

performance characteristics that have resulted in expanding use of these

materials in the aerospace industry apply to industrial and automotive applications but, as indicated on the next slide, there are a significantly different

set of constraints on the technical and economic impact in the two areas: The

factors that are critical to widespread use in industrial and automotive

applications are primarily cost related, and include the cost of the reinforcement, the concept of hybridization (combining minimal levels of higher performance, higher cost reinforcements with lower performance, lower cost fibers),

P43-4
high throughput fabrication capability, and fully optimized composite design.

These differ from those in aerospace/aircraft in sensitivity to materials

costs, fabrication methods, production rates, product form requirements, and

the absolute level of mechanical performance necessary.

The fabrication issue can be simply depicted as shown on the next slide: The

aerospace industry--in which major structural use of composite materials had

its genesis and has its learning curve--is characterized by low production

volumes and high labor intensity, as represented by hand lay up procedures and

long cure cycles; although, as manufacturing demands increase, emphasis is

also being given here to lower cost, higher rate manufacture. Cost effective

use in industrial/automotive applications necessitates a quantum change in

manufacturing rates and methods, with attendant major implications on types of

resin systems used, product forms, control of fiber placement and orientation

during the manufacturing process, and quality assurance.

Consider now a second aspect of maximizing cost effectiveness: hybridization.

Successful use of hybrid composite materials is extremely significant to major

penetration of these high volume, cost sensitive markets, and the next slide

depicts a representative hybrid material form that meets the objectives of

reducing cost by minimizing the percentage of high performance reinforcement

(carbon fiber in this case), maximizing performance by optimizing carbon fiber

placement, and creating a product form amenable to high speed fabrication.

This is effected by placing unidirectional carbon fiber on the surface of a

hybrid molding compound with a comparatively cheap chopped glass core. The

relative content of the various materials making up this type of hybrid are

typically 10 to 12 percent carbon fiber, on the order of 60 percent glass, and

30 percent resin.

P43-5
It is key to note that the materials cost of this kind of construction is not

much different than that for other high performance polymeric materials and

these relatively small amounts of carbon fiber result in major increases in

performance characteristics such as tension and flexural stiffness; similar

conclusions also apply to fatigue endurance, for example.

There has been extensive prototyping of automotive components in carbon fiber

and hybrid materials, although this is now reduced, and the extent of what has

been done is, perhaps, best represented by the widely publicized program

completed by Ford in 1979 where they undertook to build an experimental car

with body, chassis, and powertrain components from carbon fiber composites to

the maximum extent. A schematic breakout of this vehicle is shown in the next

slide: In constructing this car, about 160 parts were made in carbon fiber

reinforced composites, resulting in a total weight save of over 1200 pounds

(706 lbs by direct materials substitution, 540 lbs as a result of secondary

weight reduction), and an increase in fuel efficiency of 33 percent. Since

this program--which was focused on concept and materials feasibility as opposed

to primary manufacturing and cost considerations--further analysis and prototype

demonstration has shown that, depending on vehicle, type of component, and

hybrid utilization, materi al cost penalties of $1.50 to $0.70 per lb. of

weight saved are quite realizable with carbon fiber composites (with fiber

prices at levels well below those available today). Equally important to

realize is that the thrust to use composite materials for weight reduction is

also leading to extensive evaluation of glass only systems--both unidirectional

and high glass content chopped systems--in structural applications, and that

these can be highly cost/performance effective (for example in certain leaf

springs)--! ess weight saved but substantially reduced cost. These points are

P43-6
illustrated in the next slide comparing the use of glass and carbon composite

materials in generic structural types for a specific vehicle. The net result

is that with the growing depth of understanding of the performance characteristics, and advantages, of these materials, and the availability of sophisticated

design techniques which permit that definition of the total stress environment

for anisotropic systems as well as multiple material optimization--the latter

including both hybrids and combinations of metall ic/composite constructions--

there continues to be substantial effort in this area. All glass structural

applications using continuous fiber, or mixtures of continuous, unidirectional

and short fiber in random orientation, are going into production, and a number

of carbon/glass hybrid components are nearing semiproduction trials. In

Europe, the emphasis is more intensive.

Realization of this full potential for truly dramatic weight savings opportunities

in the highly cost sensitive transportation i ndustry--and the attendant implications for large substitution of metallic materi al s--i s , however, contingent on

a number of key factors, as outlined in the next slide. These include:

o Reinforcement cost

o The ultimate selection of weight targets for a given space envelope,

which will dictate the use of certain materials for design of vehicles

with optimum capacity and utility at minimum weight,

o Further development of design and materials methodology to pursue

maximum effectiveness in utilization of inherently anisotropic systems,

o Better understanding of performance characteristics in service and

failure modes.

o Development of low cost, high volume manufacturing processes.

P43-7
o Resolution of problems in bonding and joining methods, including

dissimilar materials.

o Development of higher rate methods of nondestructive testing readily

applicable to quality control.

o Further quantification of the crash-worthi ness of composite materials.

Turning now to some other aspects of the general industrial market, recall

that continuous filament reinforcement (glass and aramid) of plastic matrices

have been used to a significant extent for various types of pressure container

and piping applications where high specific strength is the principal mechanical

performance requirement, and light weight and corrosion resistance are also

often significant objectives. This general type of application is being

extended to the transportation industry in the filament winding of railroad

tank cars. With respect to the utilization of higher performance reinforcements,

the current thrust and future potential is briefly summarized in the next

slide: At present, the most significant use of carbon fibers in industrial

applications is in chopped reinforcement of thermoplastic molding compounds,

with performance emphasis on static dissipation (due to the electrical conductivity of carbon fiber) and lubricity; these systems also take advantage of

the well developed, low cost manufacturing advantages of injection molding.

Typical applications include data printer parts, ignition components, and x-ray

tables and cassettes--the latter of which exploit the x-ray transparency of carbon

fiber composites permitting lower intensity radiation to the patient. Projected

future applications in this segment, which include oil drilling equipment, agricultural equipment, heavy machinery, and chemical plant equipment, take broader

advantage of composite performance characteristics, i.e., structural rigidity

and light weight, fatigue resistance, reduced inertial resistance for high speed

reciprocati ng and rotating action, and chemical and corrosion resistance.

P43-8
In summary, the principal nonaircraft/aerospace applications of high performance

composites cover a very broad range of existing and potential uses in diverse

market segments--mari ne , recreation, transportation, and industrial. The

former two represent areas of well established applications; the latter two

encompass more limited use at present, but have the greatest volume potential.

Indeed, with respect to the latter, full resolution of the major issues--

reinforcement cost; fully optimal use of hybrid systems; development of high

speed, automated manufacturing processes that permit reliable control of fiber

placement and orientation--could result in larger scale use and substantial

metal replacement.

P43-9
SUBSTITUTION PREPAREDNESSINFORMATION STOCKPILE ON SUBSTITUTION TECHNOLOGY

A. 0. Schaefer

Metal Properties Council

P44
KEYNOTE ADDRESS

SUBSTITUTION PREPAREDNESS

INFORMATION STOCKPILE ON SUBSTITUTION TECHNOLOGY

BY

A. O. Schaefer

Executive Director

The Metal Properties Council Inc.

P44-1
Substitution Preparedness - Information Stockpile on

Substitution Technology.

Requirements for an information stockpile on substitutes

for critical materials. How should it be developed? Mechanism

for storage and dissemination of technological information on

substitution. How does it relate to existing information sources?

It is important to me to state at the onset that I

believe I have certain very definite qualifications for being on

this program. I was part of the war effort thirty-five or more

years ago when we faced the problems of inadequate supply of

alloying elements. There was an industry committee organized by

the War Production Board that was known as the "Bent Committee"

because it was chaired by one Quincy Bent,, then Vice President of

the Bethlehem Steel Corporation.

The word computer in its present sense was unknown. We

had not yet come to the recognition that the supply of the good

things on this earth was not unlimited., but we did know that we

didn’t have the capacity to acquire the supplies of the alloying

elements we would like to have in time to meet scheduled demands.

Furthermore 5 the Nazi and Japanese submarines made ocean shipments

p recarious

.

Strangely enough I don't recall any problems with

chromium. We were short of vanadium for a while because it had

P44-2
- 2

-

to come all the way up the West Coast of South America. In the

latter days of the war we lacked columbium because we didn't know

where to find it.

But we were in relatively short supply in everything,

and we attempted to control the distribution to where it would be

the most needed. The WE steels and their role has been referred to

by others at this meeting. The "leaner alloy" principle was widely

practiced. The experience leads me to one conclusion which I think

has a bearing on our consideration of our planned information system.

The properties we thought we needed of the NE steels

and the other leaner alloys, were rather easily obtained (life was

simpler in those days), -- but the manufacturing technology and. the

plant equipment needed to get the necessary results with the

leaner alloys was the major problem, and we had many meetings and

plant visitations by experts to teach how to get the necessary

results with leaner alloys. The exchange of technology, not

properties of substitute materials^ was a major problem and I

think we should be aware that there will again be problems in this

respect

.

Briefly, as an example, here was the requirement for

cannon barrels. We needed more of them, of lighter weight, capable

of utilizing more powerful explosive charges, producing higher

muzzle velocities, and having lower alloy content. We did it by

P44-3
-3-

bettering our melting, forging, and heat treating operations, -- and

there was a great exchange of technology both here and in Britain

to accomplish it.

Now for today. We are of course, discussing a popular

subject. Our public, at least the engineering public, is aware

that resources are dwindling. They are aware the materials we

need may be cornered in unfriendly hands. Outside of the metallurgical

fraternity, there may not be awareness of the extent to which this

applies to our raw materials, but we have some basic public

awareness to build on.

Our technical societies have addressed this problem,

and the American Society for Metals is in the forefront of this

activity. I am sure Dave Chafe will tell you of this.

My present experience is with The Metal Properties Council,

Inc., where we have one important task group on the Use of Computers

in Managing Material Property Data. One of our panelists is a

colleague of the chairman of that Task Group, Jim Graham.

MPC has another task group on "Critical Materials"

which is chaired by Ray Lula, whose name has appeared in our

discussions here. This group has reported to ASM’s committee on

this same subject. It was organized, at the request of several

members to consider what might need to be done with respect to

P44- 4
-4-

substitute materials. The principle interest of course, would be

the engineering properties of such materials. MPC would feel a

responsibility to state what data was needed to proceed to obtain

it, validate It, and make it available where it is needed.

This young Task Group , several members of which are

attending this conference, has announced two conclusions which I

think should be more widely known, and which are pertinent to

this discussion.

The first of these is that we should not confuse the

two quite different aspects of the critical materials problem.

The one aspect is that of the critical materials situation which

would come from a war or similar crisis of finite and limited

duration. The second is the long-range problem based on the

ever-shifiting economic and political situation and the world

supply of critical materials.

The first is more acute; but, in many respects, the

simpler phase of the problem. The second is certainly more complex,

and presents us with entirely new situations.

The second pronouncement of the MPC Committee has to

do with stockpiling and need not concern us at this session.

The long range situation is one which requires better appreciation

P44-5
-5-

of the problem on the part of all elements of our population.

Societies such as the American Society for Metals, government

bureaus such as the Department of Commerce and the Department of

the Interior must continue to impress the public with the facts

of the situation, with the knowledge of our dependance on foreign

sources for many of our metals. Effective efforts for conservation,

innovation in substitution can only be expected when there is

widespread appreciation of the situation. This does not involve

information—stockpiling of the type contemplated in the title

of this session. Our attention today, is quite similar to that

of our MFC task group, it must be directed to making readily

available to those who will use it, the properties of all possible

substitute materials.

Before embarking on long-range planning for the information

stockpile on critical materials, let us make clear that we should

recognize the difference between the standardized and static information which rightly belongs in handbooks and forms a necessary

base for our information.

We are more concerned, I think, with the advancing front

of new knowledge of the properties of materials. The accumulations

of new data for which we have new and effective tools for evaluation.

It is expressed in this sentence borrowed from a recent issue of a

British publication, "Materials in Engineering"

"Optimization of design and specification

of engineering components and systems to meet

P44- 6
- 6

-

life cycle demands in terms of initial, through

costs, and acceptable safe life, demands a greater

knowledge of long term material properties and residual

safe life than can be derived from conventional

property data."

This to me explains why we have expanding programs of

ever more sophisticated testing producing data which is subjected

to more revealing analysis. This is taking place today with

conventional materials. It will take place with substitute materials.

The problem is to analyze and evaluate data properly,

and to make it readily available. This is exactly our problem

with substitute . materials

.

It is well to consider briefly some of the efforts

that have been initiated in this field as an introduction to today's

discussion. The American Society for Metals has been outstanding as

one of our major technical societies offering extensive handbook

and computer information services. Other technical societies have

similar activities. We will not enumerate here all of the data

sources available to us today.

We should mention a review and report which was conducted

by a committee organized by the Numerical Data Advisory Board of

the National Research Council which was chaired by Mr. James

Graham, who is also chairman of the MPC task group and whose colleague

P44- 7
-7-

appears on our program today. Their report, published in late

1980 ., is entitled "Mechanical Properties Data for Metals and

Alloys: Status of Data Reporting, Collecting, Appraising, and

Disseminating.

A listing of the members of the Committee appears as

Figure 1 and you will note the participation of many present at

this conference. Furthermore many present today from various

government bureaus, notably from the Bureau of Standards and from

the Department of Defense met with this committee and explained

their activities and interest.

I think it is pertinent to today's discussions to extract

from the very important report of this Committee, two of their

conclusions. These are shown in Figures 2 and 3.

These should be considered in planning activity in this

area.

Another interesting publication of The American Society

of Mechanical Engineers, will be available next week at the

meeting of the Pressure Vessel and Piping Division of that

Society. It is entitled "Critical Issues In Materials and

Mechanical Engineering" and is identified by ASME as PVP Vol. 47.

Section 1.2 of this document is entitled "The Role of

P44-8
-9-

Engineering Judgment and the Computer in the Management of Material

Property Data." The activity reported in this hook was chaired

by Dr. Jeffrey Fong of the National Bureau of Standards. The

section in question emphasized the fact that great value must be

placed on engineering judgment in the evaluation of metal properties

and I would join in this opinion which is based on genuine experience.

One of the commentators in the book expresses it in this form.

li The management of the computer system must reside in those familiar

with materials and understanding the meaning of the property data,

n rather than with the computer technologist per se.

I would like to mention one more publication which is

available because several of the members of this panel contributed

to it, and expressed their thoughts in it. It is entitled "The

Use of Computers in Managing Material Property Data." It is an

ASME publication, identified as MPC-14. A look at the title

page indicates the participation of members of this panel. It is

shown in Figure 4.

I hope that these remarks will prepare you for the

opinions and statements of the experts you are about to hear.

The needed information necessary to stockpile consists of (1)

the availability of materials, and (2) developments on substitutions

for scarce materials.

P44-9
PANEL ON MECHANICAL PROPERTIES DATA FOR METALS AND ALLOYS

James A. Graham, Chairman

Deere & Company Technical Center (Metal Properties Council)

Herbert L. Black

Universal Cyclops Specialty Steel Division

Cyclops Corporation (Steel industry)

M. K. Booker

Oak Ridge National Laboratory (Nuclear materials)

Paul Brister

Babcock & Wilcox

(American Society of Mechanical

Engineers)

Herbert Corten

University of Illinois (University)

Stewart Fletcher

American Iron & Steel Institute (Steel industry)

W. J. Harris

Association of American Railraods (Rail industry)

Ronald Landgraf

Ford Motor Company

(Society of Automotive Engineers)

Joseph F. Libsch

Lehigh University

(Federation of Materials Societies)

(American Society for Metals)

Art Lowe

Babcock & Wilcox (Nuclear design)

Adolph Schaefer

Metals Properties Council

United Engineering Center (Metal Properties Council)

Henry Streraba (Deputy Managing Director,

American Society for Testing and American Society for Testing

Materials m. . . and Materials)

P44-10
CONCLUSION NO. 3

THE PANEL STRONGLY RECOMMENDS THAT MECHANICALPROPERTIES DATA BE ADDRESSED THROUGH THE ESTABLISHMENT AND MAINTENANCE OF SEVERAL SPECIALIZED DATA BANKS

DEVELOPED BY TECHNICAL EXPERTS/ RATHER THAN BY A

SINGLE ALL-ENCOMPASSING ONE. SUCH SPECIALIZED DATA

EFFORTS SHOULD BE COORDINATED. THE PRESENT DATABASE MANAGEMENT SYSTEMS BEING DEVELOPED BY THE METAL

PROPERTIES COUNCIL AND THE DATA PROGRAMS AT BATTELLE/

OAK RIDGE NATIONAL LABORATORY/ AND INDUSTRIAL AND

OTHER ORGANIZATIONS SHOULD BE CONTINUED AS A PART OF

SUCH A COORDINATED SYSTEM.

P44-11
CONCLUSION NO 7

WITH THE ADVENT OF COMPUTER-AIDED MANUFACTURING AND

AUTOMATED PROCESSING, DATA BASES MUST INCLUDE THE

MECHANICAL PROPERTIES AND TEST METHODS THAT HAVE

BECOME INCREASINGLY IMPORTANT IN THE PLANNING OF

MANUFACTURING PROCESSES AND IN THE CONTROL OF THESE

PROCESSES TO ASSURE CONTINUOUS QUALITY PRODUCTION.

P44-12
CONTENTS

The Development and Use of Mechanical Properties in Industry

R. IV Lanograf and A. Conte 1

The Mechanical Properties Data Center and Numeric Online Information Systems

H. Mindlin and G. J. Kovacs 13

The Metal Properties Council Materials Properties Data Storage and Retrieval System

J. A. Graham 23

New Methods for Analysis of Materials Strength Data for the ASME Boiler and

Pressure Vessel Code

M. K. Booker and B. L. P. Booker. 31

List of Related Titles 65

P44- 13
INFORMATION ANALYSIS CENTERS AND SUBSTITUTION TECHNOLOGY

Harold Mindlin

Battel le Colunbus Laboratories

P45
INFORMATION ANALYSIS CENTERS

AND

SUBSTITUTION TECHNOLOGY

Paper to be presented at the

Workshop on Conservation and Substitution

Technology for Critical Materials

15-17 June 1981

Vanderbilt University

Nashville, Tennessee

by

Harold Mindlin

Manager, Materials Information Program Office

Battelle's Columbus Laboratories

505 King Avenue

Columbus, Ohio 43201

P45-1
INFORMATION ANALYSIS CENTERS

AND

SUBSTITUTION TECHNOLOGY

by

Harold Mindlin

The Metals and Ceramics Information Center and the Mechanical

Properties Data Center have been in operation since 1956 and 1960, re- spectively (Slide 1)*. These Department of Defense full-service Information

Analysis Centers (IAC) have become resources used by the government, industry, and academic technical communities for the rapid retrieval of materials

information and data. With the relatively recent move toward computer-aided

design and manufacturing, the selection of materials becomes another facet

of the process needed to produce efficient structures and components that

must operate under various conditions in a variety of environments. The

information and data in these two Centers provide a data base that can become an integral and essential part of any materials system designed to

accelerate and facilitate conservation and substitution.

It is the objective of this talk to describe current activities

and suggest alternatives and data base modifications that will extend the

usefulness of these Centers within the current levels of technology displayed

by the mechanical properties numeric data base. Keeping in mind that a modified MPDC/MCIC data base can become part of an integrated computerized

system, the problems of substitution and conservation, the topics of this

conference, will be addressed.

The objective (Slide 2) of all the Information Analysis Centers is

the increased productivity of the technical community involved in scientific

and engineering programs. Through the collection, review, analysis, appraisal, and summarization of the available data, scientific and technical information is made available to the Centers' users.

*Copies of slides are attached.
2

These steps in the processing of technical information obtained

from a number of sources (Slide 3) permit the evaluation of the data to

occur at several stages —from review of incoming data in its original form

by qualified technical personnel and information specialists to the review

necessary for the summaries which are produced in a number of formats.

For aerospace and other alloys of concern to the DoD, the foregoing sources are reviewed to provide authoritative (and evaluated) information (Slide A) on design characteristics, applications, processing,

fabrication, quality control, environmental effects, test methods, sources

(suppliers) and specifications.

In order to gather this information and make it available to all

potential users, the operation of each of the Centers is divided into three

task areas (Slide 5)

1. Establishement of the data base—including (a) acquisition and

input of source information (b) initial review for pertinence

to overall scope (c) evaluation and extraction of data and information and (d) inputting of data into appropriate data

system (MCIC or MPDC)

2. Products and Services

a. Technical handbooks and databooks (our current listing

contains about 15 titles)

b. State-of-the-art reports (more than 40 titles)

c. Critical reviews and technology assessments (on request)

d. Responses to technical inquiries (about 270 per year)

e. Responses to bibliographic inquiries

f. Special studies and tasks (about 14 on the current contract totalling about $1.4 million)

3. Public Relations

a. Current Awareness Bulletin (issued monthly with emphasis

on DoD activities)

b. Promotion and sales (sale of Handbooks and State-of-theArt Reports permits additional technical activities)

P45-3
3

After the information is reviewed, key-worded, abstracted, etc.,

it is entered into a common bibliographic data base (Slide 6) . In addition if there is numeric and sufficient characterization data on the

mechanical properties of alloys of interest to the Centers the data are entered into the Battelle system. The bibliographic data is entered into

the Defense RDT&E On-Line System at the Defense Technical Information

Center through two terminals at Battelle. This information then becomes

available to anyone having access to the DTIC system or through the services

provided by MCIC. The numeric data base on the Battelle computer is managed

by Battelle's Automated Search Information System (BASIS), a versatile

(proprietary) data management system. BASIS has many features that permit

ease in searching, on-line editing, sorting, and report generation. Data

manipulation, statistical analysis, file creation, saving of user procedures

can be handled by the system. Battelle' s computer is accessible through

TYMNET, an international telecommunications network. Although MPDC can be

addressed through TYMNET, that service is not yet available. It is hoped

that In the future the MPDC data base will be made available to outside

users

.

The remainder of this presentation will focus on the operating

system and contents of the MPDC numeric data base with the intent of showing, by example, the inherent capabilities of BASIS as it is applied to

the problems of data storage and retrieval. The mechanical properties

numeric data base is currently comprised of two separate sections that

eventually will be combined (Slide 7). The Thesaurus is an Alloy Cross

Index (that is available in published form) set up on an alloy numbering

system unique to MPDC. Originally this was done to facilitate searching

of the data base. The Thesaurus contains U.S. and foreign specifications,

chemical compositions, common nouns, and other descriptive terms, etc., of

many alloys —all related through the MPDC number.

The main portion of the numeric data base are the data files that

contain —Source identification —Material identification and/or characterization —Specimen, test, and environment descriptions —Test data (for individual specimens)

.

P45-4
A

To illustrate the ease with which the data base can be queried,

a search example (Slide 8) is given to retrieve tension data (1) for a bar

(2) material having less than 20 percent chrome (3) at test temperatures

of 60-80F. For this example, there are 20 records that the search criteria

(Set 6) identified as having one or more sets of specimen test results.

Alternative search routines (Slide 9) based on "AND” statements can be used

to arrive at the same results.

A typical record would have all the available information to

characterize the material as well as give the data (Slide 10). After the

appropriate test results have been identified in the data base, the information can be reformatted to put the data into a more readable form (Slide 11) or data from different reports can be analyzed or reformatted in tabulated

or graphical form. As indicated previously, analysis programs (Slide 12) and

results can be stored for future reference. In addition, plotting routines

are available (Slide 13) to combine data from different records.

With this background, the question "How can similar data and capabilities be applied to solve the problems related to conservation and substitution?" can be posed. MCIC and MPDC have evaluated data from a variety

of sources—but, much more is needed if the data are to be used to conserve

strategic materials or select possible substitutes or alternatives for an

alloy that is in short supply or just not available. As demonstrated with

the MPDC example, the computer hardware and software (such as BASIS) are

available to facilitate access to extensive quantities of relevant data.

In order to select a "non-critical" material for a specific

application, it is necessary to extend the contents of the MPDC data base

and define the search parameters. The proper combination of these parameters

will then define a usable material providing for an acceptable design meeting

design life or environment criteria and/or other restrictions.

As a start, for a given material, this requires an integrated data

base containing evaluated data, such as —Physical Properties —Product Forms —Fabricability

--Mechanical Properties —Service Environment

--Corrosion Resistance.

P45-5
5

Within each of these categories (Slide 14) , the data must be as complete as possible if all aspects of the problem are to be addressed. For example,

mechanical properties may be given as specification values or as calculated

mean values (with standard deviations) for a representative population (MIL

HDBK 5C approach) . (This is considerably different than the individual

data points given in MPDC.) Additionally, it may be necessary to represent

properties, such as fatigue or stress-strain behavior in a mathematical

(curve) form. Background information such as test specimen characterization

and test description, may be stored, but it is not of direct importance to

material selection. One of the key limiting factors of this proposed sophisticated data base is the amount of data and the degree to which it can be

evaluated and integrated.

As a relatively simple example (Slide 15) , this system could be

queried by specifying that the alloy requirements are

1 . no chromium

2. weldable (process may be specified)

3. formable

with related strength requirements in a given environment such as

4. minimum yield or fatigue life at a given

number of cycles and temperature

5. corrosion resistance

If one remembers that a relatively simple search routine can specify these

variables, these parameters can be entered into the system with the results

being a list of materials and/or a combination of materials and processes

meeting those requirements.

This, and the related physical property data, can then be entered

into a computer-aided design process to assure that the structural needs such

as minimum weight or life can be achieved. If all goes well, various material sources can be contacted. One or more iterations through the CAD process may be required depending upon material delivery, structural weight,

cost, etc. (Factors such as quantity requirements that could affect availability are not addressed in this presentation. Sources and quantity effects

could be the topic for another paper.)

P45-6
6

As one can easily see, the complexity of the system requires the

assembly of a large quantity of evaluated data. A strong materials/structures/information interface is required to produce a system that will be

easily accessible, complete, and contain adequate data. Some of the other

speakers have described such systems for specific applications; hence, we

know that given the proper resources, steps can be made toward the solution

of the problems of substitution and conservation.

P45-7
METALS AND CERAMICS

INFORMATION CENTER

MECHANICAL PROPERTIES

DATA CENTER

FULL-SERVICE INFORMATION ANALYSIS CENTERS

Operated under Contract to

DEPARTMENT OF DEFENSE

By

BATTELLE'S COLUMBUS LABORATORIES

6/25/79

*4# Baneiie

Columbus Laboriiories

P45-8
OBJECTIVE

\

\

i

INCREASED PRODUCTIVITY - SCIENTIFIC AND ENGINEERING

PROGRAMS

FUNCTIONS

6/2S/79 QBattelle

Cnlumbu* laboratories

P45-9
I

INFORMATION RESOURCES

- GOVERNMENT REPORTS - CONTRACTOR REPORTS - U.& AND FOREIGN LITERATURE - PUBLISHED AND UNPUBLISHED COMPANY STUDIES - BATTELLE STUDIES

- INTERVIEWS AND TRIP REPORTS

I

i - TECHNICAL MEETINGS AND PROCEEDINGS

v

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C/2S/79 Columbus Laboratories

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P45-10
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P45-11 (

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TASKS

ESTABLISHMENT OF THE DATA BASE — ACQUISITION AND INPUT OF SOURCE INFORMATION

PRODUCTS AND SERVICES — TECHNICAL HANDBOOKS AND DATABOOKS — STATE-OF-THE-ART REPORTS - CRITICAL REVIEWS AND TECHNOLOGY ASSESSMENTS — TECHNICAL INQUIRIES — BIBLIOGRAPHIC INQUIRIES — SPECIAL STUDIES AND TASKS

PUBLIC RELATIONS — CURRENT AWARENESS — PROMOTION AND SALES

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P45-14
SEARCH EXAMPLE-1

ENTER YOUR REQUEST

1/TT: TENSION

200 ITEMS SAVED AS SET 1

2/FM: BAR

1 50 ITEMS SAVED AS SET 2

3/CR 0.0/20.0

75JTEMS SAVED AS SET 3

4/(1 AND 2 AND 3)

50 ITEMS SAVED AS SET 2

5/TMP 60/80

40 ITEMS SAVED AS SET 5

6/(4 AND 5)

20 ITEMS SAVED AS SET 6

P45-15
SEARCH EXAMPLE - 2

ENTER YOUR REQUEST

TT: TENSION AND FM BAR AND

CR 0.0/20.0 AND TMP 60/80

ITEMS SAVED AS SET

PA5-16
ITEM 1

0. ACCESSION NO.

15. POINTER

21. NAME

23- PORK

24. ELEHENT(WTJ)

:241*99

: 1635

:64 19

:BAR-ROUND , 1.675 IN DIAMETER

;N I : ;CR: 18.0 ;CO:14.6 ;TI:4.68 ;K0:3.1 ; AL:2.5

;V: 1 . 47 ;FE:0.14 ;KN:0.1 ;C:0.07 ;5I:0.10

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DENSITY

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CAGE LENGTH : SPECIMEN CONFIG : TEST TYPE

SPEC ORIENT : TEST RATE :

: WROUGHT , FORGED

:0 . 292 LBS/IN (3

)

: PRE-HEAT - SOLITTION TREATMENT - COOL OR QUENCH

TO ROOM TEMP

.•MULTIPLE AGE

: 2150 , 4.0 , ,AIR COOLED TO ROOM TEMPERATURE

, A IR COOLED TO ROOM TEMPERATURE

, ,AIR COOLED TO ROOM TEMPERATURE

4.0

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TENSION

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AFTER YIELD THE HEAD SPEED WAS INCREASED

TO 0.1 INCH/MIN . FAILURE.

79.9 - DEG. F

177.000; 178.000; 178.000;

138.000 - 0.2*; 139.000 - 0.2*; 137.000 - 0.2*;

30.900 ;27.900 ;28.900 ; 7.20 ; 7. 70 ;6.70 ; 7.00 ;9.60 ;9.50 ;

BatTelle

P45-17
HPDC DOCUMENT NO.: 241499

NAME: 6419 FORM: BAR-ROUND, 1.875 IN DOCUMENT : 1635

DIAMETER

ELEMENT WEIGHT %: HI: ;CR:l6.0 ;C0:14.8 ;TI:4.88 ;M0:3.1 ; AL:2.5 ; W:1.k7 ;FE:0.14 ;KN:0.1 ;C:0.G7 ;SI:©.10 ;B:0.0l8 ; ZR: 0. 04 ;S:0.003 ;

PROCESSING INFORMATION

PRIMARY OPERATION: WROUGHT, FORGED

THICKNESS: DENSITY: 0.292

SPECIMEN DATA

NOTCH CONFIGURATION: STRESS CONC FACTOR: 1.0

SPECIMEN CONFIGURATION: ROUND SPEC, LG OF RED. SECT 2.500 IN.

HEAT TREATMENT

TYPE TE^P, HOURS, MEDIUM, REMARKS

MULTIPLE AGE 2150 , 4.0 ,

, AIR COOLED TO ROOM TEMPERATURE

1975 . 4.0 , , AIR COOLED TO ROOM TEMPERATURE

1550 , 24.0 , .AIR COOLED TO ROOM TEMPERATURE

1400 , 16.0 ,,AIR COOLED TO ROOM TEMPERATURE

NOTES: PRE-HEAT - SOLUTION TREATMENT - COOL OR QUENCH TO

ROOM TEMP

TEST DATA

TEST TYPE: TENSION TEMP: 79-9 - DEG. F THICKNESS: 0.500

GAGE: 2 TEST RATE: 0.005 INCH/INCH/HIN . IN THE ELASTIC

REGION. AFTER YIELD THE HEAD SPEED WAS

INCREASED TO 0.1 INCH/HIN. FAILURE.

ORIENTATION: LONGITUDINAL ENVIRONMENT:

FAILURE DESCRIPTION:

UTS YS KE( •

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EL RA

177.000 138.000 - 0.2* 30.900 7.20 7.00

178.000 139-000 - 0.2$ 27.900 7.70 9-60

178.000 137.000 - 0.2$ 28.900 6.70 9-50

EK.ER REPORT DIRECTIVE

/

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DATA ANALYSIS AND PRESENTATION

• STATISTICAL ROUTINES - REGRESSION ANALYSIS - PARTITIONING. LEAST-SQUARES

- CURVE FITTING

- MEAN. STANDARD DEVIATION. DISTRIBUTION (NORMAL

OR NON-NORMAL)

- A AND B DESIGN ALLOWABLES

• ELEVATED TEMPERATURE RATIOS (MIL-HDBK 5 PROCEDURES)

• COMPARISON OF MATERIAL DATA FOR LOT-TO-LOT VARIATIONS

• MECHANICAL PROPERTY PLOTTING ROUTINES

6/25/79 ©Battelie
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P45-20
DATA REQUIREMENTS

Physical Properties Product Forms

Chemical Composition

Eustic Constaitts

Density

Thermal Properties

Hardness

Wrought

Cast

P/M

RST

Fabricability

^chining

Forming

Welding

Tempering

Coatings

Plating

Surface Treatments

P45-21
DATA REQUIREMENTS (Continued)

Tensile

Compressive

Bending

Torsion

Impact

Creep

Stress Relaxation

Service Environment

Media Composition

Temperature

Length of Exposure

Pressure

Particulates

Velocity

Mechanical Properties

Fracture

Fatigue

Crack Propagation

Bearing

Shear

Multi axial

Corrosion Resistance

Base Material

Surface Treatments

Stress-corrosion Susceptibility

Load Interactions

P45-22
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Columbus

laboratory-
INFORMATION AS AN ESSENTIAL ASPECT OF CONSERVATION

H. David Chafe

American Society for Metals

P46
INFORMATION AS AN ESSENTIAL ASPECT OF CONSERVATION

H. David Chafe

Director, Metals Information

American Society for Metals

P46-1
//, JW/

Titl e: Information as an Essential Aspect of Conservation

It is gratifyi ng, and I am tempted to add 'at this late date 1 , to find a recognition of the importance of information ... or perhaps information

science and its present-day capabilities ... in the context of a national

emergency, and it is encouraging that we have this session on information

included in the workshop.

The problem of unavailability or shortage of strategic materials is to

some degree addressable in terms of stockpiles of those materials, but

this can at best be a temporary measure. Conservation and substitution,

by whatever means, offer longer term solutions and effective use of the

lead time available for these solutions will be found in a number of

presently available and forthcoming information resources.

'Lead time', as mentioned, implies that action must be taken in advance of

an emergency. Repeated experience, and this is direct experience in metals

information, brings home the fact that information sources, traditionally,

seem to be consulted when all else fails. In vthe jargon, current

awareness searching is used very seldom in comparison with retrospective

information searching and the lesson is clear ... 'keeping up' or 'keeping ahead' is not yet viewed as the prerequisi te; we are still in the

mode of reacting to 'what went wrong?'

This workshop, I must hasten to add, is a strong indication that the

value of information science may be at a turning point. We, as

individuals and representatives of organizations concerned with

materials availability, are fortunate that one crisis in advanced, or

P46-2
- 2 -

advancing, technology is concurrent with another advanced technology

that can supply many of the ansv/ers.

No one today questions the capabilities of computers; we can assume that

there is a machine to do what's needed. The questions are, again

What's needed?, and

What's available?

To a surprising degree, what needed _i_s_ available and there are

indications that what is needed and not yet available is forthcoming.

The remaining and persistent problem will be awareness . In relation

to this, I would like to address the two fundamental types of computerized information resource which we have working for us in this

country. These are:

Bibliographic files, and

Numeric data files

sometimes differentiated by database and data bank , in turn.

I have used the term "information resource " and, since it fills my

purpose so well, would like to show you the dictionary definition.

Resource, n. 1. something that lies ready for use

or can be drawn upon for aid ; supply of something

to take care of a need .

2. usually in pi. something that a country, state,

P46-3
3. a means of accomplishing something; measure or

action that can be resorted to, as in an emergency;

expedient: as, his only remaining resource.

4. ability to deal promptly and effectively with

problems, difficulties, etc. ;

SYN. - resource applies to anything, person, action,

etc. to which one turns for aid in time of need or

emergency .

Considering these types of resource, bibliographic and numeric, in

turn:

Bibliographic Databases : Figures compiled by the National Federation

of Abstracting Services for 1980 shov/ that the member and affiliate

organizations of the Federation, 45 in number, generated abstracts and

indexes for nearly tv/o and a half million published papers. In the

organizations dealing with technical papers having greater or lesser

bearing on materials, 15 of these organizations handled a total of

1,417,200 papers. While recognizing but not documenting some overlap

in coverage, the number will still be impressive, and more impressive

still is the fact that these document surrogates were substantially a]J

entered into computerized bibliographic databases. For the most part,

abstracts journals are now photocomposed, and a counterpart computer

tape is a standard by-product of the typesetting operation, along with

the typeset pages.

The primary factor in this proliferation of databases, of course, is

the emergence of the telecommunications network coupled with the

P46-4
- 4 -

simplicity of telephone/terminal /computer access. The Lockheed DIALOG

System, operating from Palo Alto, CA, and with essentially worldwide

access to its computers in that location, currently provides 110

databases online (in widely varying fields), servicing many thousands

of terminals and available at least 8 hours a day in most countries.

To provide an example, perhaps I might be forgiven for taking metal

s

as central to materials . Metals Information, with its offices in

Metals Park, Ohio (at ASM) and in London, England (at The Metals

Society), currently monitors over 1200 technical journals, in addition

to comprehensive coverage of conference papers, technical books and

dissertations, and selective coverage of patents and government

reports. This is done as the initial stage of the publication of

Metals Abstracts and its related indexes. Its computerized offshoot,

the METADEX database, has been building for sixteen years and now

contains bibliographic records of approximately 450,000 documents.

Approximately 38,000 document surrogates in the form of abstracts and

indexes entered the file last year. At the present time, nearly 800

terminals worldwide access this database each month for an aggregate

connect time amounting to over three hundred hours. In all, perhaps

2000 separate locations access this one database occasionally or

consistently.

Now, going on to

Numeric Data Banks : While the software for manipulating and locating

numerical data online is necessarily different from bibliographic

software, the telecommunications network capability is in place and

can serve either purpose equally well.

P46-5
Access to either numerical or bibliographic information, of course, is

a model of simplicity with telephone dial-up direct to the computer

through local nodes of the network. This avoids extensive longdistance phone bills and for the most part the major online services

require no up-front charges; costs are based on access time and units

of information printed out.

Training in use of numeric databases will necessarily be more demanding

than with bibliographic files. In the latter, while the subject matter

may differ considerably , the basic SELECT/EXPAND/COMBINE/DISPLAY orders

are generally the same file-to-file and system-to-system; Boolean algebra

is the working tool in almost all cases, combining some terms and

excluding others.

Because of the relative complexity of numerical files, a generalized

training approach will not work as easily across data banks, and subject knowledge will have to be a stronger prerequisite. In other words,

numerical data banks will probably be the catalyst in producing the next

generation of information searcher, and the source of the next (to use

an overworked expression) "information explosion". This growth will be

demonstrated, and already is appearing, with the search terminal that

you will see on the desk of the individual engineer or scientist, rather

than (as now) being restricted to the library or information center,

with a third party as interface. Equipment costs for terminals, modems,

printers and the like have dropped steadily, to the point where purchase

is perhaps more likely than lease, and only access costs will be of

financial concern. The multiplication of terminals at this point will

probably work towards reducing these access fee rates.

P46-6
- 6 -

Within the next five years, I believe we will begin to see this kind

of synergy, with widespread, easy access, at reasonable cost and in the

first person ... the kind of access previously available only through

handbooks and exhaustive library time, but with the advantages of computer-based recall, scope and speed.

The across-the-board scope of the METADEX bibliographic database,

covering all metals and both physical and extractive metallurgy, has

governed our thinking in relation to numerical data banks. Most, if

not all, of the existing data banks have considerable depth of data

over a fairly narrow band of materials. We have been concerned with

the need for a broadly-based file, answering the majority of questions

such as we receive daily by telephone and letter, and dealing with all

types of alloys.

We have now found the basis for this file in the machine-readable

counterpart of two recent ASM publications which were designed to

provide a correlation for nonferrous alloy and steels designations to

the worldwide specifications covering these alloys. Composition and

mechanical property values were included for many thousands of materials

from twenty countries. The publications are: Worldwide Guide to

Equivalent Irons and Steels and Worldwide Guide to Equivalent Nonferrous

Alloys .

Computer-based access to such compilations can and does offer substantial advantages over the traditional indexing of the sort found in

handbooks. The standard publication indexes to the Worldwide Guides

addressed the alloy designation and specification number only. In the

P46-7
- 7

-

computer file, any element of the information may be requested singly,

or combined with any others, or indeed may operate with specific

excl usion of certain data elements.

Additionally, computer operation of such a file can utilize number

searching (which, of course, can also be done for fixed numbers in a

free text bibliographic search) but can also go beyond this to searching

ranges of numbers. In other words, a search for steels with 0.06-0.10 C

will specify the range and will also pick up steels containing 0.07 C,

0.08 C etc. Beyond this, a second level of ranges is usable in the

property field, so that values of composition and (for example) tensile

strength required can be asked for together or singly.

It is obvious, of course, that the machine-readable content of two books,

extensive though they may be, is only a starting point. Where the books

leave off, there must be some means of providing continuous updating,

not only for the inclusion of more alloy designations and their related

property data, but also for the alteration and editing of existing alloy

representations . The latter aspect must include the capability for increasing the number of properties and the inclusion of more than one

estimation for a given value.

Metals Information is in a unique position to provide this continuing

updating, in terms of source material. The first of these will draw on

the editorial operations of ASM's Reference Publications department who

will continue to update the Worldwide Guides, and will coordinate any

and all other data collection operations in their publications program

through machine-readable means.

P46-8
- 8 -

Our other updating mechanism will draw from the so called "open literature". In the production of Metals Abstracts each year, the U.S. and

U.K. offices regularly scan over 1200 technical journals, and they

utilize every available method in obtaining the worldwide conference

papers, technical books, plus dissertations, patents, government reports,

pamphlets and the like. This results in a process of narrowing down

from the hundreds of thousands of papers in these sources, to, as last

year, the selection of 38,000 technical papers suitable for inclusion in

Metals Abstracts/ and the METADEX database.

A further reduction then occurs in the selection of those papers appropriate for use in a sister publication to Metals Abstracts called Alloys

Index . This publication is based on those papers which specify

individual alloys (whether designated by an alphanumeric, as a trade

name, or compositional ly) . We find that approximately one-quarter to

one-third of the papers going into Metals Abstracts have reference to

the alloys, metallurgical systems and intermetal 1 ic compounds such as

are indexed in Alloys Index. This would mean that perhaps 8-10,000

papers per year are candidates, and the real ly» appl icable subset can be

determined readily in the existing editorial procedures.

Editing and updating procedures for the numerical database will utilize

the present input equipment which connects Metals Park online to the

computer center at a distance of twelve miles away for the production

of Metals Abstracts. Records may be called up on-screen to display

current status, and deletions, changes or additions may be made instantly.

The record input will be entered complete with typsetting codes, in order

that publications may be drawn from the data bank at any time, and with

the content designed as needed.

P46-9
- ‘J -

We are currently agreeing on a contractual arrangement with a major

online network to make the data bank available worldwide within a few

months. Update input specifications are also being completed, and

production updating will commence within the next two months.

All the foregoing having been said, it is realized that this undertaking

is not designed for everybody's requirements, especially in the need for

the most immediate experimental data, with multiple representations of

datapoints and such refinements as extrapolations, curve fitting, or

computer graphics. It will, however, grow rapidly into a widely available resource with potential for rapid lookup of information that would

be expensive, time-consuming or impossible to find by traditional

methods. As time goes on and the rate of addition of alloy representations to the file necessarily dwindles, greater depth of information,

such as wear or corrosion characteristics, or thermal properties, for

example, may be added to the individual alloy records.

A further possibility is the potential for cross-referencing to the

bibliographic records in METADEX, so that the source paper for the

recorded values may be consulted.

To return to the basic problem that we are addressing, it is interesting

to review some of the subject matter being discussed throughout this

meeting, in relation to conservation of strategic materials. There are

papers dealing with such subjects as:

Reduction of Cobalt in Gas Turbine Engines

Substitutions for Chromium in Spring Steels (and similarly

in Magnetic Alloys, or in High Speed Steels)

P46-10
10 -

Potentials for Claddings/Coatings to Conserve Critical

Metals

Conservation of Critical Metals by Surface Alloying

Alternate Methods for Improved Performance (as with

Rapid Solidification)

The two types of database I have outlined can and do address all of these

problem areas, can locate prior experience, and can, at the very least,

speed up our reaction time in an emergency situation. And as we react,

or as the situation should develop, it will be all the more important

that rapid dissemination of the answers be pursued by all available

means.

To quote Dr. Y. S. Touloukian, Director of the Center for Information and

Numerical Data Analysis and Synthesis, otherwise known as CINDAS:

" ... we must realize that our (national and corporate)

technological advantages are of little benefit unless they are

put to practical use within a relatively short time lapse. At

the National level, perhaps the most self-defeating aspect of

information usage is the unnecessary delays in its application

to our technology. At times we observe that our adversaries

and friends alike seem to be able to deploy U.S. technology

more rapidly than the U.S. does."

While we recognize some unfortunate truth in this, it is encouraging

to come upon a further quote, this time from the Chairman of the House

Science Subcommittee who recently referred to

P46-11
11

"the profound impacts of the Information Revolution on our

economic prosperity, our national security, and our social

and political institutions."

It is very fortunate that, to a large extent, industry will be in a

position to, as the quotation said, deploy U.S. technology and a great

deal more of the world's technology , if proper use is made of the

existing U.S. lead in information techniques and resources.

P46-12
FACTORS INFLUENCING A NATIONAL MATERIALS

SUBSTITUTION INFORMATION DATA BASE

Hour ice A. H. Howes

ITT Research Institute

P47

Contribution to

WORKSHOP ON CONSERVATION AND SUBSTITUTION

TECHNOLOGY FOR CRITICAL MATERIALS

Vanderbilt University

Nashville, Tennessee

15-17 June 1981

FACTORS INFLUENCING A NATIONAL MATERIALS

SUBSTITUTION INFORMATION DATA BASE

Maurice A. H. Howes

IIT Research Institute

Chicago, Illinois 60616

There are many fragmented data bases available containing

information about material substitution which could be integrated

to provide data concerning potential substitutions. This is perfectly possible but, if done, would ignore some of the more

important aspects of substitution. To make this point clear,

the factors influencing the material substitutional data base

will be considered.

There are two main potential users of a substitution information data base:

1) Policy maker

2) Designers and engineers

Each requires a different type of information to serve distinctly different needs within the same framework of material

needs and supplies.

Policy makers tend to talk about material substitution as

if the alternate material can directly replace the original material. In some instances this, of course, is possible, but for

most applications a change in material requires a redesign of the

product. This design-material interaction is a major factor to

be considered in evaluating a material substitution data base.

P47-1
The policy maker needs information to help decide what substitutions are needed in the national interest. For this activity

he needs

1) Information on current resources and reserves

of material held in both the public and the

private sector.

2) Materials requirements to meet a mix of

products nationwide. The mechanism for

deciding what the mix should be is outside

the scope of this discussion but is of

vital importance to the material substitution policy maker.

3) Sufficient information to forecast supplies

of material, the demand by industry and

government , and the price of materials

.

Economics cannot be ignored when considering substitutions. Price elasticity of

critical materials should be correlated

with potential supplies.

An engineer or designer needs different information from a

national materials data base:

1) The data base should give complete information on the properties of materials. This is

largely available, but there are many gaps in

the data. It should also be recognized that

there are two sets of material properties, the

first being the properties of the material

P47-2
that affect component performance such as

strength, hardness, fatigue resistance,

corrosion resistance, etc., and the other

being material properties that affect manufacture of the product such as machinability

,

hardenability , weldability, formability, etc.

2) The choices of alternate materials that are

available in a particular national emergency.

This information will be developed jointly in

coordination with the policy maker.

3) Fabrication methods available for respective

substitute materials and the implication on

manufacturing processes.

However, a designer or engineer working at an individual

company needs far more information than this, much of it specific

to his own company operations.

1) The requirements of the product are the first

consideration. This includes an analysis of

what the component or assembly is actually

supposed to do and should not involve design

at this stage. Once the essential function

and requirements of the component are decided,

then the first elements of design can be

attempted.

2) There are usually many acceptable permutations

of design, materials, and manufacturing methods

P47-3
that will solve the problem and meet the

requirements, but only one will optimize

the lowest initial cost. Probably a different combination will optimize lowest

life cycle cost and yet another combination will optimize least use of strategic

materials. The design will probably alter

according to which material is being conserved. Some designs depend on the availability of specific classes of materials.

If it were required to build a jet engine

without cobalt or chromium being used, it

might mean that the engine would have to

run at a lower temperature and thus be less

efficient and therefore larger as would the

airframe need to be to contain it. Thus,

the impact of a change in one component may

be felt throughout the entire product. The

same design considerations have to be given

to all components within a total assembly,

and so the tradeoffs become extremely complex,

probably needing CAD-CAM methodology far more

advanced than that available today.

3) A final consideration is what a manufacturing

company is able to perform itself. Just because a material selection system suggests a

P47-4
way of manufacturing a ;part does not necessarily mean that a company would be able to

do so. The company may not have the capacity

available to increase the use of any specific

manufacturing method or may not even use it

at all. Then the decision has to be made

between increasing capacity, subcontracting,

or using another apparently less optimum method

of manufacturing.

In conclusion, the problems of setting up a data base to

cover materials alone are immense but, with logical steps, surmountable. However, such a data base will be of limited use

unless manufacturing processes and design/material interactions

are considered. CAD-CAM techniques can be applied to optimize a

design to whatever parameter is believed to be most important at

the time of consideration, be it cost or minimum usage of a strategic material or the maximum use of a nationally available manufacturing capability.

The U.S.A. is highly vulnerable to material shortages that

are beyond its control, and it is critical that strategies be

developed for such crises. A national material substitution data

base as described above could be of substantial value to policy

makers and to engineers and designers. Development of such a

data base would be a major undertaking, but without such a starting point , national response to material shortages would be panic

with little available guidance. Stockpiling of critical materials

P47-5
has long been considered. However, it is even more important

bo stockpile the information needed on how to use alternate

materials. It is very important that action be taken now to

establish a Material Substitution Information Data Bank.

P47-6
INFORMATION REQUIREMENTS WHEN FACED WITH A MATERIAL SHORTAGE

Bruce E. Boardman

Deere & Company

P48

INFORMATION REQUIREMENTS WHEN FACED WITH A MATERIAL SHORTAGE

B.E.BOARDMAN

INTRODUCTION

During the last two and a half days we have heard many talks which

approach the problem of dealing with a material shortage. Most have

dealt with the problem from only one of many ways. This is not

wrong since each may have only one "solution". What I would like to

do in the next few minutes is to explore the range of "solutions"

which need to be considered prior to the selection of which is

appropriate in any one case.

I should point out that in the ground vehicle industry the problem

may generally fall into the simple cases but the logic used to

determine the path to follow should not change.

FACTORS TO CONSIDER (IN REVERSE ORDER)

In this first section I wish to deal with three areas which need to

always be considered: The range of options which may be taken, The

scope of the problem, The purpose of the "problem" material. Note

that the order within which these items need to be considered is

exactly reverse from which I will present.

Range Of Options Which May Be Taken

The range of options which may be taken span the entire

possibilities from the easy to the difficult. The choice of

which to consider will be dependent upon the reasons for a substitution of material and/or process and the economics

envolved. The purpose of the material and the scope of the

problem must have already been determined.

Change Chemistry For Equivalent Response

The simplest and generally the most economic action is to

change one alloy for another. In order for this to be

effective, and the rational, is the premise that the two

elements are equivalent. We have heard several talks where

hardenability was the primary need to consider and in these cases alloy substitution will be the easiest and least cost

method. Along those same lines, the substitution of different

grain refiners will effect least cost solutions to material

shortages. We could include with that the use of other

elements besides magnesium in the production of nodular iron.

Enhance Performance Of Lesser Material

This may be accomplished by mechanical processing, thermal

processing, or both. The net result is to produce a material

which is equivalent to the predecessor while eliminating the use of a critical element. The use of high strength low alloy

P48-1
steels is an example of this as is the normal heat treating of

parts. Although heat treating is considered normal activity

there will be parts where, for economic reasons, . alloy

materials are used while similar parts could be made from heat

treated non-alloy or low-alloy materials.

Reduce Requirements Through Redesign

Frequently a simple redesign will be able to correct a condition which reduces the requirements on a part to a level

which will allow a lesser material to perform satisfactorily.

This is not to imply that the resultant part is less adequate,

only that due to the design change the performance is

equivalent. As example were the grain refiners found in the

formable grades of steel to become unavailable it could be

that changes in bend radius would allow other less formable

materials to be used successfully.

Base Alloy Substitution

When it is the base alloy or an alloy which comprises a major

portion of the material which is in short supply significantly

more effort may be required in order to provide an equivalent

part. With major alloy changes the first trial will be for a similar alloy with similar properties. Unfortunately this

will only be satisfactory in a small number of cases. The

alloys which were chosen originally were generally chosen for

special attributes which were otherwise not available. Such

things as creep resistance, strength at elevated temperature,

electrical or thermal conductivity, and corrosion resistance

frequently required very special materials with special

properties. Substitution will not be easy or straightforward

Total Function Redesign

The redesign of a system may be the last recorse when the

material shortage is so extreme that there are no other

material or processing options. This will be the most

expensive and time consuming method to satisfying the problem

but this method must be kept open. Within this scope of

redesign is meant those drastic changes which result in the

function of the entire system being performed in a different

way.

Scope Of The Problem

As part of the problem and therefore of the solution is the scope

of the shortage problem. The expected duration and economic

penalities associated with not changing need to be considered.

There are four causes for a shortage which come to mind as the

primary reasons and each could dictate a different path depending

on which one was the cause. The first two relate to the

economics of the material and are therefore controlable and

action is optional. The later two are not predictable or

P48-2
controlable and are the more serious of the problems faced by

materials engineers.

Supply Exhausted

A completely exhausted supply of a material is the most

extreme condition with which we must deal. Fortunately there

will be warning signs which were observed and heeded prior to

the actual last bit being consumed. These warnings would have

allowed time to plan and adjust the subject parts and

functions well in advance of the final moment. Frequently the

planning for a material’s demise could last over several years

so that the impact would only be felt by those who were not

listening. In the last several years the cost of the material

should skyrocket therefore driving the holdouts away for

economic reasons.

Economics Of Obtaining

As a material nears its end the cost will increase. This does

not mean that a user must stop using the material, only that

the cost of the final product will increase. It is likely

that cost will finally drive the product off the market prior

to the total depletion of material.

Temporary Shortage

The temporary shortage is a nasty condition since it is

normally unpredictable and occurs without warning. One

difficulty is that the temporary solution may be very little

different from the solution were the supply totally exhausted

but without the time to react. Changes made frequently will

not be reversible.

Politicially Created Artifical Shortage

The politicially created shortage is artifical. It may range

from no supply available to a supply but at an inflated price.

There will be no clear cut route to take since the condition

may change back and forth at any time.

Purpose Of "problem" Material

The final area to discuss which is also the first area to

consider when faced with a material shortage is a critical answer

to the question "What is the purpose of this material?"

Base Material

Is this shortage with the base material without which the

design cannot be made. If so the materials engineer will be

in a deep hole. Is there another material which is similar

enough to satisfy the requirements with only minor change in

design or cost.

P48-3
Primary Alloy

Shortage of an alloy which is primarilly responsible for the

behavior of the part. As above then another similar material

may be considered.

Secondary Alloy

There is a lesser problem if the shortage is in one of several

alloys which together produce and effect. Most frequently

this is the condition with hardenability and other common

steel alloys. This option may not be available for the

superalloys common to the high temperature jet engine,

gasification, or nuclear industries.

INFORMATION REQUIREMENTS

Effect Of Alloy

Mechanical Properties

Response To Thermal/Mechanical Processing

Cost and Current Availability Of Substitutes

Future Projected Cost And Availability

ACCESS REQUIREMENTS

Ways To Explore Options

Online Data Access

Ways To Reduce Trivial Or Non-Essential Information

All Previously Discussed Information

P48-4
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P48-11
SUBSTITUTION PREPAREDNESS -

THE INFORMATION STOCKPILE ON SUBSTITUTION TECHNOLOGY

John Rumble

National Bureau of Standards

P49
COMMENTS ON

"SUBSTITUTION PREPAREDNESS -

THE INFORMATION STOCKPILE ON SUBSTITUTION TECHNOLOGY"

Given by

John Rumble

Office of Standard Reference Data

National Bureau of Standards

Washington, D.C. 20234

at the Workshop on Conservation and Substitution

Technology for Critical Materials

June 17, 1981

Vanderbilt University

Nashville, Tennessee

P49-1
I would like to thank Alan Gray of ASM for inviting me to talk here today.

Certainly the sessions held during the past two-and-a-half days have highlighted the problems for both our national economic well-being and our national

security of our present day dependence on materials either in short supply or from foreign sources. The past two-and-a-half days have also focused on ways

of implementing the four strategies to reduce these dependencies, namely, by

substitution with materials of equal or better properties and performance, by

displacement with materials with lesser properties but about equal performance,

by conservation of materials by new processing and fabrication technologies,

and by recycling of these materials after use.

Today, we are focusing on what has been called the "Information Stockpile"

required to implement these strategies. In my talk (outlined in figure 1), I want to discuss four aspects of these data needs which I firmly believe play a fundamental role in providing a framework for building such an information

stockpile. The first will be a review of the fources which have changed in

the past few years to allow us to consider actually making such a stockpile

now. The second will outline the different types of data involved and their

relationship to the motivating forces described previously. The third will

address the different needs of the private and public sector for materials

information. The last will be concerned with the need for evaluation as a critical component for several key types of data. After this, I will briefly

describe the NBS materials sciences data programs and outline the role they

might play for information on critical materials.

The underlying basis for this entire discussion needs to be clearly stated

from the beginning. The task of creating all, or even a significant part, of

an information stockpile on critical materials is large, complex, and impossible

for any one organization or activity to complete. The considerations which I describe will hopefully allow the diverse data activities, present and future,

to maintain a clear perspective, both of what they can and should do and of

what others can do, recognizing the limited resources available.

Why Now?

The data needs of many parts of the materials community have been the subject

of several studies in the past decade, some of which are shown in figure 2.

Not remarkably, these needs have not changed appreciably, even for those

specific data needs directly relating to relieving dependence on critical

materials. This is not remarkable because the basic problems of expense,

availability, and performance have been with the materials community from

earliest times. But two important factors have changed recently (figure 3),

namely, the ability to understand and predict material properties and performance

and the ability to accumulate and distribute the resulting knowledge. The

first of these has played a primary part in the discussions of the past two

days as evidenced by the new technologies and materials talked about. The

second is a reflection of the computer revolution, the impact of which is

still growing by leaps and bounds. Quite simply, we can generate better data

and can make it available more easily.

P49-2
Let me demonstrate these new capabilities by posing a materials design question

in two entirely different ways (figure 4). Upon reflection, each of the

questions is even more complex than is obvious at first glance. Everyone in

the materials community wants to combine economic data, processing technology

data, basic scientific and technical data, and performance data in one way or

another. From our own experience, we all realize how difficult it has been

to have access to and to use the handbooks, cost sheets, and manufacturer's

specifications for these data. I am not suggesting that an all-encompassing

data base which instantly answers these questions can be built, even within our

lifetime. That will be discussed more later. But if we refer back to the four

strategies to reduce our dependence on critical materials--substitution, displacement, conservation, and recycling--we can imagine that individual data

bases will soon exist which should be able to answer quickly parts of similar

questions which arise from pursuing each of these strategies. Why is now the

time for creating the data resource on substitution technology? Because more

and better data are available and because computers will allow us easily to get

at these data.

Types of Data

The use of a particular material in a given product requires many considerations:

cost, weight, performance, reliability of supply, ease of fabrication, and numerous

others. It is instructive to refer to one version of the materials cycle which

also contains the flow of information relevant to each stage of that cycle

(figure 5). This particular representation has been adopted from one given in

a report on Information Systems Supporting U.S. Materials Policy done by the

Office of Technology Assessment for the U.S. Congress in 1976. The information

that is shown on this picture can loosely be classified as economic, technical,

and political. Some of the actual data falls in two or three of these categories,

but let us concentrate on the technical data only, particularly those data needed

for substitution analysis and material production for critical materials in

figure 6. First and foremost, data are needed to characterize the physical,

chemical, mechanical, and performance properties of presently utilized materials

containing one or more critical materials. A more detailed list of these

properties is given in figure 7 for substitution analysis. Clearly these data

are what material and product designers now use, implicitly and/on explicitly,

relying on whatever sources with which they have become familiar and comfortable.

In addition, formal data activities in many of these areas now exist, mainly

sponsored by the Federal Government. It should be pointed out that, without

exception, these data centers are all in severe need of more resources.

The next types of data needed are the same physical, chemical, mechanical, and

performance properties of alternative materials, those either substituting or displacing substances containing critical materials and those resulting from

greater use of recycled, and probably contaminated, materials. Lastly, a more

complete list of data needed to aid in designing and implementing new, improved

material production technologies is given in figure 8. Such data cover an amazing range of disciplines, from thermodynamic data needed for the roasting

of ores to metastable phase data for rapid solidification technology to data

used to predict the mechanical properties of components cast into near-net-shapes.

P49-3
The data needs outlined above are by no means exhaustive, but they lead to

what I consider to be the most important conclusion regarding technical data

needs. That conclusion is that materials designers and producers need many

diverse types of data simultaneously (figure 9). It might be pointed out

that this is neither startling or new. But its implications for existing and

future data activities are large. Presently, most, if not all, materialsrelated data work is discipline oriented. The Battel le Metals and Ceramics

Information Center ;s Mechanical Property Data Center is concerned with mechanical

properties. The NBS Alloy Phase Diagram Data Center is concerned with alloy

phase data. Purdue's CINDAS Data Center is concerned with thermophysical

properties. But to date, even though it is recognized that the need exists

for data users, in this case, the materials designers and producers, to access

a lot of different data all at once, no data activity has had the resources or charter to do this.

Let me reiterate this last point. If the materials community is going to be

serious about development an information stockpile to reduce the U.S.'s

dependence on critical materials, then this important need to access simultaneously several different data bases must be fulfilled.

Public and Private Data

With these cross-disciplinary needs well in mind, let us now consider how these

needs might be satisfied and in what form. As a preliminary, it should be

noted that even though there is an overdependence on critical materials such as that outlined over the past two days, that in itself would not be bad if there were one hundred percent assurance that supply changes would be orderly and

not subject to artitrary and unpredictable disruption. But our experience of

the last decade makes us believe otherwise.

Because we cannot predict when the problems will arise, two time scales

(figure 10) are important for developing the needed data bases and information

collections. The first is long-term and is based on the economic principle

that a particular materials company can best maintain its long-term competitiveness by gradually i ncorporati ng new processes and utilize alternative materials

in a systematic fashion over a period of time, such that when the crunch comes,

the adverse effects are minimized.

The second time scale is that defined by a disruption, especially an unpredictable

disruption. The needs of society met by the materials industry will remain, and

the company able to respond just as quickly as it did the day before the

disruption will do the best economically.

It is more, however, than just the private sector which has a concern with both

of these time scales. Certainly for defense purposes, it is clear that we must on the long-term take the needed steps to relieve gradually our dependence

on the critical materials. But even more important, if and when the disruptions

do occur, it will likely be a time of increased defense needs, the fulfilling

of which could be most important to our survival. We must be able to respond

quickly in this situation.

P49-4
What all does this have to do with the idea of an information stockpile? The answer is that there are two separate data needs, one related to the private

sector and economic competition, the other related to legitimate national

interests, and they need data for different reasons and at different times.

Further, as pointed out earlier, there is a new large effort needed to integrate,

in some unspecific way, existing and future discipline-oriented data activity.

It is a fact that, to date, most materials data activity available publicly

has been federally sponsored. There are some notable exceptions, especially

for the publication of handbooks by technical and industrial groups. There is

a good reason for this Federal involvement. Most competitive companies in the

materials industries have developed, in one form or another, their own internal

data sources. These are usually a combination of published data and proprietary

data. There is a natural reluctance for these companies to share their data

with their competitors. Realistically, within these internal data bases,

little of the proprietary technical data is unavailable to others from other

sources or is critical to the company's survival, especially on an item-byitem basis. But the value of having collected it and the ease of use by their

own technical people can provide a company with a critical competitive edge.

Because of the above considerations and the large cost of any type of information

stockpile, it is obvious that activity will be necessary on several different

levels and that cooperation between the private and public sectors will be

necessary. In particular, the Government will need to continue to support,

and in fact increase support for, specialized scientific and technical data

activities on a discipline basis. The integration of these and other data

bases into a public information stockpile will most likely take place in more

than one way and will need the strong backing of individual companies, industrial

groups, and the Government. This kind of cooperation has already started to some degree as shown by the recent efforts by the Metal Properties Council and

its work on mechanical property data and the joint American Society of Metals/National

Bureau of Standards program for evaluation of alloy phase diagrams.

Evaluation of Data

I wish to make a couple of brief but important points concerning the need and

role of evaluation in an information stockpile such as is under discussion.

It should be evident to everyone who has given thought to building materials

data bases that such data bases cannot simply be a blind collection of information.

In many respects, the material sciences have less developed methodologies, for

characterizing both properties and materials, than say chemistry. In addition,

the inherent specimen-dependent nature of some properties gives rise to a real

need for the information stockpile builders to examine carefully the included

data to insure that the material studied was well characterized and that the

material dependence vis-a-vis specimen dependence of a given property has been

well documented.

An example is the melting point of a pure metal on different alloy phase

diagrams. Obviously, it must be the same regardless of the system. For instance,

in a well-known collection of phase diagrams, the melting point of titanium is

reported as 1660, 1680, and 1720 C for different titanium alloy systems (figure 11).

This example of an almost trivial piece of data suggests how large the problem

will be for complex materials and less well-defined properties. Such evaluations

can only be done by state-of-the-art materials people.

P49-5
This means that evaluation will be expensive, but it must be done this way

for the data collection to be useful.

The National Bureau of Standards Data Programs

The NBS Office of Standard Reference Data (OSRD) Materials Sciences Data Program

is designed to provide needed physical, chemical, and metallurgical data for a better understanding of solid materials and their use (figure 12). Presently

the main effort is directed towards compiling, evaluating, and disseminating

basic data about phase equilibrium and crystal structure. OSRD helps support

four data centers concerned with these data, which are fundamental in characterizing solid materials. In addition, another data center is concerned with

transport in solids. Figure 13 gives some information about all of these centers.

Phase equilibrium data are compiled by two separate data centers, one for

alloys--the Alloy Phase Diagram Data Center, and one for cerami cs--the Phase

Diagrams for Ceramists Data Center, both at NBS. The Alloy Center has been

working closely with the American Society of Metals to set up and implement

a program to evaluate systematically phase diagrams for binary and higher-order

alloys. This program will be described in detail below. The Phase Diagrams

for Ceramists Data Center has recently been discussing a similar program to be

done with the American Ceramics Society. The hope is to increase greatly the

coverage and publication frequency of the ceramic phase diagram series. Such

a program will undoubtedly enhance access to evaluated non-metal! ic phase data.

Data on transport in metals, especially mass transport and diffusion phenomena,

are the scope of the Diffusion in Metals Data Center at NBS. This data center

maintains a comprehensive collection of relevant literature and, for certain

substances, performs in-depth evaluations and reviews. The data center is just

now finishing a second volume concerning the diffusion of copper in various

substances, which work has been jointly sponsored by the International Copper

Research Association (INCRA).

Crystalline structural data are the concern of the NBS Crystal Data Center

and the Cambridge Crystal Data Centre. Both of the centers maintain computerized

files on substances subjected to crystallographic analysis. In the next few

months, the NBS Crystal Data Center will begin distributing via an on-line

computer network a data base for the identification of crystalline materials

using single crystal diffraction data. The data base contains over 60,000

compounds.

In making a list of important materials properties, certainly phase equilibrium

data are among the most important. Indeed, to talk intelligently about other

properties of a material, it is necessary to be able to specify the stable phase(s)

of that substance under the desired conditions. The NBS Alloy Phase Diagram

Data Center has started a joint program with the American Society of Metals

to provide a systematic effort to evaluate all existing phase data for metal

alloy systems. This work will update and supercede the compilations by

Hansen and the additions by Elliott and Shunk.

As shown in figure 14, the program has five components. The binary systems and

the Bulletin of Alloy Phase Diagrams have already started and will be described

in detail below. The higher-order systems program is just beginning to get

focused. Because of the greater number of higher-order systems, it is crucial

P49-6
to identify important types of systems and to coordinate any new evaluation work

with existing efforts. Hand-in-hand with the phase diagram evaluation program

is the use of computers in disseminating the results as shown by items 4) and

5) in figure 14. Computer graphics research done by the Alloy Data Center has

produced software which can generate phase diagrams of publishable quality.

In figure 15, the complete phase diagram for the lead-silver system is shown, and

figure 16 demonstrates the ability of the computer graphics program to expand

the detail on a particular section, in this case the lead-rich portion. Such a capability is particularly attractive for more complicated diagrams such as in

figure 17, that of the mercury-uranium system, where it is difficult to see all

the detail in one diagram. Eventually this graphical information will be combined

in a public data base with the appropriate thermodynamic, crystallographic , and

supporting information, but it will be a while before such a data base is available.

This is one example of the integration of discipline-oriented data bases which

I mentioned earlier.

The evaluation program for binary allow phase diagrams is well under way. The

program is well organized so that for each set of systems there will be a separate editor who will work under the editor-in-chief, Professor Ted Massalski

of Carnegi e-Mel Ion. Work is presently under way for several systems, including

alloys containing V, Ti, Ag, Zr, Zn, Cd, and Be. Four other systems, Cu, Ni , the

alkali metals, and the rare earths will soon be started. The evaluations

will not only contain the actual phase diagrams drawings but also will include a thorough discussion of the experimental work, phase structural data, thermodynamic

data, and references. Information on metastable phases will be included as available and appropriate. The output will be published both in the Bulletin

of Alloy Phase Diagrams and as monographs.

As International Council on Alloy Phase Diagrams exists, and the members

contribute to the NBS/ASM program, both as individuals doing evaluations and

as members of working committees. The council has played an important role in

identifying other evaluation efforts and in helping to set out evaluation criteria.

The power of the program is derived from two separate aspects. The first is the

systematic evaluation by recognized experts of phase data for all binary systems.

The second is in the phase diagram data bank which will likely be an important

component of any information stockpile on critical materials.

One other important part of the NBS/ASM joint program is the publication of the

Bulletin of Alloy Phase Diagrams (figure 18). This bulletin is designed to put

evaluated phase data in the hands of users quickly and in an easy-to-use manner.

The second issue has just been distributed. Among other things, it features

computer-generated phase diagrams such as those shown before.

OSRD also supports data programs in many other areas. Some of the ones of

particular interest to the materials community include Chemical Thermodynamics

,

Fluid Transport Properties, Chemical Kinetics, and Molten Salts. Information

on any of these programs can be obtained by contacting the Office of Standard

Reference Data at NBS.

P49-7
Summary

In closing, I would like to reemphasize a few points made above. First, the new advances in generating materials data and in computers has allowed us to

consider for the first time creating an information stockpile on critical

materials. But the effort will be large and expensive and will require close

cooperation of the private and public sectors, especially to insure the limited resources available are not used to duplicate work.

P49-8
COMMEN TSJill .ItlF.QRMAT I ON _SIQ.CKP I

L

E

FOR SUBSTITUTION TECHNOLOGY

I. Important Considerations

Why Now?

Types of Data

Public and Private Data

Evaluation

II. NBS Materials Sciences Data Program

Figure 1 P49- 9
PR EVIOUS STUDIES ON MATERIALS INFORMATION

(Partial List)

1964 Dissemination of Information on Materials,

Materials Advisory Board, NAS

1969 Proceedings of National Engineering Information

Conference, Office of Science and Technology and

Engineers Joint Council

1970 A Systematic Evaluation of Materials for Structural

Application

1972 National Materials Advisory Board, NAS

Report on Survey of Materials-ori ented Scientific

and Technical Societies' Information Service

Federation of Materials Societies

1974 Requirements for Fulfilling a National Materials

Policy, Office of Technology Assessment (OTA)

U.S. Congress

1975 Federal Materials Research and Development:

Modernizing Institutions and Management

GAO

1976 Technology Assessment of Materials Information Systems

IBM

Fiaure 2 P49- io
1976 An Assessment of Information Systems Capabilities

Required to Support U.S. Materials Policy Decisions

OTA, U.S. Congress

1978 National Needs for Critically Evaluated Physical

and Chemical Data

Numerical Data Advisory Board (NDAB), MAS

1980 Mechanical Properties Data for Metals and Alloys

NOAB, NAS

P49- 1

1
° Better Data Available

° Computers are Better

Figure 3

P49-12
QUESTIONS

1. HOW CAN WE MANUFACTURE HIGH PERFORMANCE AIRCRAFT

ENGINE TURBINE BLADES WITHOUT CHROMIUN ?

2. HOW CAN WE DESIGN A NEW

HIGH STRENGTH (Steady State creep down to 0,2%

IN 8-10,000 HOURS, HIGH TENSILE

STRENGTH, DUCTILE, LOW CYCLE AND

THERMAL FATIGUE RESISTANT)

HIGH TEMPERATURE ( 1200-1600 C ) CORROSION RESISTANT (Max 10 mils in 10,000 hrs

penetration)

GOOD FABRICABILITY AND WELDABILITY

LIGHTWEIGHT MATERIAL ?

Figure 4

P49-13
Basic Informational Framework Applied to Materials Substitution

SUPPLY CONSIDERATIONS

UTILIZATION CONSIDERATIONS

Figure 5 P49- 14
SCIENTIFIC AND TECHNICAL DATA IN THE MATERIALS CYCLE

Substitution Analysis

Material Production

Mining

Refining

Smelting

Fabrication

Manufacturing

Existing Materials >

Physical

Chemical

Mechanical

Performance

Alternative Materials

Figure 6

P49_15
SUBSTITUTION ANALYSIS

Scientific and Technical Data For Existing and New Materials

Physical Properties

3ensity

3ardness

Coefficient of Friction

Viscosity

Porosity

Permeability

Reflectivity

Chemical Properties

Corrosion

Reactivity

Solubility

Thermal Stability

Oxidation

Sulfidation

Crazing

Thermal Properties

Conductivity

Specific Heat

Coefficient of Expansion

Melting Point

Mechanical Properties

Tension

Stress-Strain

Tensile Properties

Modulus of Elasticity

Compression

Bearing

Shear

Fatigue Strength

Creep

Crack Propagating

Resistance

Impact Resistance

Wear Resistance

Stress Corrosion

Cavitation

Electrical Properties

Dielectric Constant

Conductivity

Figure 7

P49-16
MATERIALS PRODUCTION

Mining

Refining

Smelting

Fabrication

Weldability

Mach i nab i lity

Heat Treatability

Formability

Forming

Sheet Forging

Plate Casting

Bar Tubing

Extrusion Powder

Figure 8

P49-1

7
MATERIALS DESIGNERS AND PRODUCERS NEED ACCESS TO

MANY DIVERSE TYPES OF DATA SIMULTANEOUSLY

Figure 9

P49_ 13
INFORMATION STOCKPILE ON CRITICAL MATERIALS

Pertinent Time

° Long Term -

0 Short Term

Scales

MAINTAINING ECONOMIC COMPETITIVENESS

EVALUATING ALTERNATIVE MATERIALS AND

PROCESSES

MEETING INCREASED DEMANDS

REACTING TO DISRUPTIONS

Figure 10

P49-19
RF PORTED MEITING POINTS OF PURE TITANIUM

Alloy System HP,

Ti - Zr 1Z20

Ti - Zn 1680

Ti - V 1Z20

Ti - U 1660

Figure 11

P49-20
OSRD MATERIALS SCIENCES DATA PROGRAM

To PROVIDE NEEDED PHYSICAL, CHEMICAL,

AND METALLURGICAL DATA FOR A BETTER

UNDERSTANDING OF SOLID MATERIALS AND

THEIR USE.

Phase Equilibrium Data

Transport Data

Structural Data

Figure 12

P4 9~2i
OSRD MATERIALS SCIENCES DATA PROGRAM

Phase Equilibrium Data

Alloy Phase Diagram Data Center - R, Mehrabian, NBS

NBS-ASM Joint Program

Phase Diagrams for Ceramists - L. Cook, NBS

American Ceramic Society - NBS Joint Program

(in formation)

Transport Data

Diffusion in Metals Data Center - J, Manning, NBS

Structural Data

Crystal Data Center - A, Mighell, NBS

Cambridge Crystal Data Centre - 0, Kennard, Cambridge, U.K.

Figure 13

P49-22
ALLOY PHASE DIAGRAM DATA CENTER

NBS-ASM Joint Program for Phase Diagram Data

1) Binary Alloy Phase Diagrams -

Comprehensive Compilation and Evaluation

Update and Replace Hansen, Elliott, and Shunk Volumes

2) Bulletin qf.Allqy Piia^TIia^ram -

A Periodical to publish "provisional" diagrams for

Rapid distribution and user feedback

3) Ternary and Higher-order Alloy Phase Diagrams

Compilation and Evaluation

Coordination of Current Efforts here and abroad

A) Computer Phase Diagram Graphics

5) Computer Data Base of Phase Stability Information

Figure 14

P49-23
Weight Percent Lead

0 10 20 30 40 50 60 70 80 90 100

Figure 15
100 Weight Percent Lead

450

u

o

<ul_

rso

i_

(uClEo

400

350

300

250

200

100 99.7 Ag

T—

L~'—'

1— 1 1 1 1 1

1 1 1 » • t

1 nr r

1

r

1 1

L

;

L + (Pb)

304°C

99 si ;

(P o)

(Ag) 44 (Pb)

|

;

: [P^ASEMAP^

i 1 j . .

.

1

99.96 \14v\

T F

1 » 99.8 99.9 Atomic Percent Lead

100Pb

Figure 16

P49- 25
T

empe

rat

u

re

o

o

800

600

400

200

0

-200

Weight Percent Uranium

0 10 20 30 40 50 60 70 80 90 100

- i t i i i i i ) t j

i i i i i i |1| i |i i i i i i^i i i |i i i i i I i r i

|

i r i r i lr i i i r i i i i i i i |i i i i i 1 i i |i i i i i i ^ i i

|

i i i i i i i |1 1

| i n mm i i i i i i i i i :+

:> <u)

7

T

> C V + (. ’(U)

66< °C

V + c ( (U)

/ V + U1 <g ( 9

) 481 i°C

v 406°C

4 82°C

375U C,

cp

CP X3

] 357°C

1 rO

_ , CT> L o

CP

' X

3

.

3 3

-38.9°C

(PHAS :map] ;

0 10 20 30 40 50 60 70 80 90 100 Ha Atomic Percent Uranium U

Figure 17

P49- 26
1

published quarterly by Amei ican Society for Petals

as part oi the American Society for ftletals/National Bureau or Standards

Data Program for Alloy Phase Diagrams p4 g

. 27
REQUIREMENTS FUR AN INFORMATION STOCKPILE

ON SUBSTITUTION TECHNOLOGY

Frank M. Richmond

Universal-Cyclops Specialty Steel Div,

P50
CONSERVATION AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS

Vanderbilt University

Nashville, Tennessee

June 15-17, 1981

REQUIREMENTS FOR AN INFORMATION STOCKPILE ON SUBSTITUTION TECHNOLOGY

BY

Frank M. Richmond

Universal-Cyclops Specialty Steel Division

Cyclops Corporation

In preparing for this brief talk on information stockpile

requirements, I personally am confronted with a situation somewhat

similar to the overall theme of this session. The efficiency of

an information stockpile program depends to a large degree on our

ability to predict the kind of information that may be required.

In my case, the challenge was to predict subjects that may not

have been covered by a prior eight speakers in this session and/or

one of the many others at one of the previous sessions.

The specific aspects of information stockpile I have

selected for discussion are:

a) How do we define a critical material?

b) Alternative domestic raw material sources (other

than domestic mines)

c) Basic R & D as an information stockpile

P50-1
CONSERVATION AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS - Vanderbilt University

Page 2

Defini tion o f a C ritica l Material

The value of a limited information stockpile on critical

materials obviously depends in a great degree on our ability to

predict what materials may require substitutuon at some point in

the future. This problem is analagous to the problem facing DoD

and FEMA in attempting to define actual national stockpile requirements. In fact, an information stockpile obviously supplements

our materials stockpile; to the extent that the stockpile goals have

been properly designed and achieved , the necessity for an information stockpile decreases - at least with respect to a national

emergency. We still, of course, are left with the potential need

for substitute materials at times other than national emergencies.

For instance, the five-fold increase in the price of cobalt between

May of 1978 and February 1979 sent alloy designers and materials

engineers scurrying to find substitutes for cobalt-containing

alloys

.

At this stage of the workshop, it is quite possible

that a critical material has been defined several times. As a

member of several committees on critical materials, I am well

aware, however, that there is no universal definition. An

excellent effort in this direction is currently being made by

Ken Stalker of General Electric, Evendale, who in connection

with the Metal Properties Council Task Group on Critical Materials

P50-2
CUNbEKVATlUN AiMU bUtJbTIT Ui ±U1M TfcCtiJNUL.ULi Y FOR CRITICAL MATERIALS - Vanderbilt University

Page 3 _

is attempting to come up with a critical element index for

eighteen metallic elements. His approach incorporates ranking

each of the eighteen elements according to twenty-one selected

factors, each of which is weighted according to its relative

importance. The index is determined by the overall weighted

ranking of each element. This approach has considerable merit

and may be of value to designers of information stockpiles.

Substitute or Alternative Raw Materials

In addition to the substitution of one alloy for another

to resolve a raw material shortage problem, we also need to consider alternatives for raw materials sources indigenous to the

United States. These include, among others:

1) the national stockpile

2) mixed and/or contaminated scrap

3) specialty steel wastes not currently recycled

The need for information on the stockpile is related

primarily to the quality level of some of these stocks. A good

example is cobalt. Most of the presently stockpiled cobalt

does not meet the chemical specifications required for melting

of critical superalloy components. GSA is attempting to

resolve this problem by purchasing cobalt to a new chemical

specification. But, in the meantime, we are missing certain

information including the actual complete chemistries of

P50-3
CUMbUKVATlUM AMU b U BbTl TUT1UJN TECHNOLOGY

FOR CRITICAL MATERIALS - Vanderbilt University

Page 4

the present stockpiled cobalt. It is my understanding that an

effort is being initiated to characterize the present cobalt.

But the plans beyond that stage are unclear. Information with

respect to methods by which the stockpiled cobalt could be upgraded would be of considerable value even if_ that upgrading

is not carried out as part of a planned program. The existence

of information with respect to what type of refining would be

required in order to utilize the existing cobalt could be of

considerable value in a national emergency. It is obvious that

if such cobalt were all that was available, specialty steelmakers

would find a way to utilize it. The value of prior information

would be in shortening the time period required to develop the

optimum method of upgrading that cobalt. A corollary would be

to develop _in advance more information with respect to certain

residual elements in critical superalloys. This would permit

producers and manufacturers to make decisions with respect to

the time and cost of upgrading versus the effect of somewhat

lower purities on material performance.

Studies of the availability of critical scrap metals

12 . containing chromium in the United States ' indicate a very

high percentage of superalloy scrap is apparently being downgraded; that is, used in less critical applications or alloys.

This not only in many instances wastes some of the critical

P50-4
CONSERVATION AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS - Vanderbilt University

Page 5

materials contained in these alloys, but significantly increases

the need for primary high quality raw materials. A follow on

program by International Nickel3 has resulted in a potential

method of reclaiming some of this downgraded material, but at

present there is no production facility to accomplish this.

In the meantime, information could be generated with respect to

a) methods to minimize the contamination or mixing of high

quality scrap so as to permit its recycling in the same class

alloy, and b) (again) more specific information on the effects

of various residuals on alloy performance. The first of these

items will be addressed in an AISI symposium to be held >in

October of 1981. The second item, which is common to utilization

of off-prime stockpiled materials, will require a comprehensive

study on the effect of individual elements in critical superalloy

applications. Some work has been done in this area, but additional

information is required to insure that we are not wasting critical

raw materials by downgrading unnecessarily.

Some feeling for the extent of this problem can be

gained by comparing the scrap usage patterns for superalloys and

cast heat and corrosion resistant alloys versus the pattern for

use of scrap in stainless steels. The percentage of home scrap

generated as a percent of total melt is not too different for

high temperature and stainless steels -- 49% versus 40% respectively.

P50-5
CONSERVATION AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS - Vanderbilt University

Page 6

The percentage of prompt industrial scrap as a percent shipped

is similar -- 25% for high temperature alloys and 19% for stainless. The percent of home scrap lost or downgraded as a percent

of that generated is similar; 13% versus 9%. The major difference

lies in the percent of prompt industrial scrap which is lost or

downgraded in high temperature metal production; namely, 62%

of the total generated versus 7% lost or downgraded for stainless

steels. Some of this difference relates to the cost of properly

segregating the high temperature scrap versus the price which can

be obtained for it in downgraded applications. In addition, there

are restrictions with respect to utilization of certain types of

scrap which are imposed by the end user. Information with

respect to the effect of various residual elements and improved efficiency of scrap segregation could significantly improve

the recycling efficiency of critical raw materials in the high temperature alloy field. This information would be extremely

valuable in the event of a national emergency or a significant

decrease in the availability of selected critical raw materials.

More information on methods to recycle specialty steel

waste products can also contribute to increased efficiency of

critical raw material recycling. This particular subject will be

the major focus of the AISI symposium previously mentioned.

Recycling information of this type will not only improve the

efficiency of our utilization of critical raw materials in normal

P50-6
CONSERVATION AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS - Vanderbilt University

Page 7 __ _ _

times, but could significantly reduce the requirement for high

quality virgin materials in a national emergency when the demand

for superalloys would be high and availability a question mark.

Basic R & D as an I nformat ion St ockpile

Obviously, basic R & D will be of little value in an

emergency situation which requires an immediate solution even if

that solution is not perfect. There are potential situations,

however, where we have time to develop completely new alloys

aimed at reducing the content of a critical raw material. As

indicated in prior papers at this workshop, several programs

are now underway in an effort to develop lower cobalt, high

temperature alloys. Basic research on the effect of cobalt,

rapid solidification technology, residual element effects, melting and remelting processes, powder metallurgy, etc. all provide

information sources that can be tapped in programs of this type.

We must increase basic R & D in the materials field in the United

States. I am deeply concerned that decreased effort in basic

R & D in the United States in the past ten to twenty years has

seriously depleted our stockpile of that kind of information.

To date, it has probably not created any major problems, but we

cannot continue to withdraw capital without sufficient replenishment. Basic research is a long-term investment. One of the

major criticisms of basic research in some quarters is its

P50-7
1 WI'J -L [ 1 IK^JjWV.1 JL FOR CRITICAL MATERIALS - Vanderbilt University

Pa ge 8

inability to provide a quick return on investment. Critics of

basic research and development complain that it is undirected,

it is not aimed at a specific problem area. This is, in fact,

one of the strengths of basic R & D. Our present inability to

accurately predict the future with respect to potential shortages

of critical raw materials demands a broad base of basic R & D,

even if such information will not solve problems overnight.

This country needs to be concerned not only with the short-term,

but the long-term. Basic R & D is an essential source of information for increased technological advances in the materials

field.

In summary, the development of an information stockpile

requires

:

1) A definition of critical materials and, if

possible, an assigning of priorities based

on expected or potential future shortages;

2) The development of information on improved

segregation of prompt industrial scrap,

especially in superalloy field as the means

of conservation and an alternative source

of critical raw materials in time of need;

3) Development of information on upgrading of

off-prime stockpiled materials to permit

their rapid utilization if a national emergency

arises

.

P50-8
CONSERVATION AND SUBSTITUTION TECHNOLOGY

FOR CRITICAL MATERIALS - Vanderbilt University

Page 9

4) Information on the specific effect of residual

or tramp elements and combination of those

elements to permit tradeoffs between the quality

of available or upgraded raw material versus

performance of alloys produced from those raw

materials

;

5) Increased basic R & D to provide information that

can be utilized in years to come as unpredictable

changes in the political, social, and economic

climate of the world create new raw material

crises

.

^-Availabili ty of Critical Scrap Metals Containing

Chromium in the United States. Part I: Superalloys and Cast

Heat Resistant Alloys. OFR No. 8(1) -80 (Bureau of Mines),

L. R. Curwick, W. A. Petersen and H. V. Makar, November 1979.

Contract J0188056.

7 . . Availability of Critical Scrap Metals Containing

Chromium in the United States. OFR (2) -80 (Bureau of Mines),

C. L. Kusik, H. V. Makar and M. R. Mounier, November 1979.

Contract J018870.

^Process for Recovering

from Superalloy Scrap. OFR 69-80

deBarbadillo, J. K. Pargeter, and

Contract J0188056.

Chromium and Other Metals

(Bureau of Mines), J. J.

H. V. Makar, April 15, 1980.

P50-9
SUBSTITUTION PREPAREDNESS -

ROLE OF COLLEGES AND UNIVERSITIES

Ellis D. Verink Jr.

University of Florida

P51
SUBSTITUTION PREPAREDNESS . . . ROLE OF COLLEGES AND UNIVERSITIES

Workshop on Conservation and Substitution Technology

for Critical Materials

15-17 June 1981

Vanderbilt University

Nashville, Tennessee

Ellis D. Verink, Jr.

University of Florida

Among the suggested responses to the critical materials problems

identified at the "Workshop on Critical Materials Needs of the Aerospace

Industry"^ in February 1981 were:

"a. A physical stockpile of critical materials of the proper

quantity , composition and form to accomodate stockpile

goals

;

b. The development of an "intellectual stockpile" of research

and development information as well as the accompanying

manufacturing technology to permit rapid substitution for

unavailable critical materials should the need exist;

c. A positive industrial effort to seek suitable substitute

materials and/or develop designs, etc., which permit use

of less critical materials or alloys using smaller

quantities of critical materials..."

The academic community can contribute to the accomplishment of each of

these responses in collaboration with industry and government.

1. Workshop on Critical Needs of the Aerospace Industry, February 9-10,

1981, NBS, Gaithersburg, Maryland.

P51-1
Background

The primary "products’’ of colleges and universities are students.

It is expected that Bachelor degree students in engineering and the

physical sciences will be well grounded in mathematics, and have a

feeling for applied sciences. To deal effectively in today’s climate,

they also should have a sensitivity regarding critical materials, think

in a "systems concept" (e.g., have an appreciation of how materials must

work together), and a working knowledge of engineering economy. To

contribute most effectively to substitution preparedness, students will

require thorough grounding in principles of metallurgy and materials in

addition to a well rounded scientific or engineering background. Bachelor

level graduates normally are engaged primarily in production and processing

of materials and general engineering pursuits.

Graduate students in metallurgical and materials engineering at the

Master's and Ph.D. level normally start with the Bachelor level training

indicated above and supplement this with advanced coursework and academic

research experience in preparation for careers in advanced technology

and research. As a consequence, a Ph.D. graduate will have demonstrated

special knowledge of research techniques, an ability to define and focus

on a research problem, and an "intuition" regarding research opportunities.

Such an intuition is especially helpful in considering substitution

preparedness

.

Faculty and graduate students at universities having graduate

programs in metallurgy and/or materials engage in research in one or

more of the basic fields of metallurgy including physical metallurgy,

process metallurgy, fabrication and joining, extractive metallurgy and

mineral processing as well as in the field of non-metallic materials

such as ceramics, polymers and composites. Faculties of such universities

represent resource pools for consultation and collaboration.

P51-2
Economic realities force individual companies to concentrate their

primary research efforts on proprietary research in support of products

and services supplied by that company. Often this results in little or

no opportunity to engage in long range activities such as fundamental

research or the storing up of substitution technology research. Industries

probably will need governmental incentives to engage in substantial

research and developmental activities to support responses (b) and (c)

above. On the other hand, universities favor research in fundamental

areas (i.e., non-proprietary research) which can be the basis of scholarly

publications, master's theses, or dissertations. This provides an

outstanding opportunity for collaborative research between industries

and universities with the universities specializing in non-proprietary

aspects and feeding the results to industries for adaptation to proprietary

interests. Likewise, research in support of conservation and substitution

technology would be ideally suited to universities. While serving these

research needs, universities also would be fulfilling their primary

educational function by producing graduates sensitized to the needs of

conservation and substitution.

Technology Transfer

The incorporation of information on substitution preparedness

technology is well adapted to normal academic activities. For example,

such information is readily included in classroom lecture material,

homework assignments, term papers, and problems. In order to accomplish

this task it merely requires emphasis on applications of materials,

selection and substitution of materials, etc. Problems requiring optimization in choices of materials based on availability, economy, net

energy costs, recyclability, conservation of critical materials, etc.,

P51-3
provide students with first-hand experience. At the University of

Florida, such activities have been in progress for several years and

student reception has been excellent. Another effective tool has been

the conducting of student contests for papers and term projects on

subjects dealing with selection and substitution of materials.

Research Opportunities

There is a wealth of appropriate research topics to challenge

graduate students while supplying vital information for substitution

preparedness. Examples of such research areas include:

1. RST materials; detailed metallurgical knowledge of mechanisms

and processes to optimize properties; characterization,

deformation processes, etc.

2. "Forgiving ceramics" - ceramics with improved ductility

or enhanced resistance to crack extension. Basic understanding, proof of concept, optimization.

3. New alloys strengthened by intermetallic compounds (e.g.,

Ti-Al, Fe-Al) - mechanisms of strengthening process,

control of properties, characterization.

4. Evolution of structure and properties of powder metallurgy

materials as a function of processing variables, composition,

etc. (e.g., aluminum).

5. Interfacial characteristics and problems related to use

of coatings containing critical materials on substrates

of non-critical materials. Mechanisms of adhesion,

resistance, protectiveness, repair, etc.

6. Mechanisms of failure of composite materials. Strategies

to avoid failure under various conditions.

P51-4
7. Alloy development focusing on systems based on available

minerals (e.g., Ni, Fe, Ti, A1 , Mo, W) and on alloys more

dilute in certain critical materials, notably Co, Cr , Cb

,

Ta.

8. etc.

Realities

The funding of universities tends to be based either on "formula

funding" or "project funding" or a combination of the two. Under formula

funding, funds are provided in accordance with the so called "body

count." This concept is particularly applicable to situations involving

very large classes such as those encountered in chemistry, physics,

mathematics, humanities, language, etc., and may also be appropriate for

certain large engineering disciplines such as electrical engineering,

mechanical engineering or civil engineering. However, in the case of

substitution technology, perhaps the most important disciplines will be

metallurgy, ceramics, polymers, etc., fields in which the total number

of students is not large. For example, during the last year there were

approximately 1,000 graduates in metallurgy produced by some 86 departments.

This gives a national average graduating class of just under 12 per

year in metallurgical engineering. The fields of ceramics and polymers

are even smaller. The industrial demand for metallurgy and materials

graduates is several times the annual production. Small disciplines

such as metallurgical and materials science are not likely to survive

under formula funding. As a consequence, a few universities have taken

steps towards project funding for such smaller disciplines. Special

efforts must be made both by industries and government (both state and

national) to be certain that vital disciplines such as metallurgy,

materials science, ceramics and polymers survive in order to assure a

P51-5
supply of prospective employees.

At present the Federal Government provides approximately 85% of the

total research support as compared with 10%-12% coming from industrial

sources. In order to maintain the research capability of universities

and colleges and to provide graduate training for personnel to handle

advanced technology in connection with substitution of materials, it is

important that there be dependable research support. Both industry and

government have an enlightened self interest in maintaining such support.

Conclusion

1. The academic community has unique capability and intellectual

orientation to participate in the accomplishment of substitution preparedness.

2. Dependable long term financial resources will be required to

assure the participation (and in a number of cases the continued existence)

of departments of metallurgical engineering, materials science, ceramic

and polymers.

3. There is another critical "commodity" for which a substitute

is not available. This critical commodity is graduates. Happily, this

is a "renewable resource" and under proper cultivation and nourishment,

the crop can flourish and help solve the problems of substitution technology . . . but help is needed

.

P51-6
SUMMARY AND OVERVIEW OF WORKSHOP

N. E. Promised Consultant

&

Allen G. Gray, General Chairman

si

Summary and Overview

of

Workshop on Conservation and Substitution

Technology for Critical Materials

by

N. E. Promisel, Consultant and

Allen G. Gray, General Chairman of Workshop

The United States is heavily dependent on foreign sources

for supplies of key materials essential to the nation's defense

and to the operation of its vital industries. This country, for

example, imports almost 100% of its strategic metals — cobalt,

chromium, columbium, tantalum, and manganese. Over-all, the

United States depends on foreign sources for 22 of the 27 metals

considered vital to the country's economy.

To meet the challenge of this enormous dependency, all

options to provide supplies or alternatives must be pursued.

On the supply side, effective steps are needed to strengthen

the strategic stockpile and to develop domestic resources. The

other option is a viable materials and processing technology for

alternatives at reasonable cost. Alternatives include substitution, conservation, enhanced performance alloys, coating and surface modification systems, and reclamation.

This workshop was developed as a contribution to the national

effort on the issue of materials dependence with the viewpoint that

technology for alternatives is among the most viable options for

reducing this country's vulnerability to strategic materials. The

message from the workshop was clear: The time to start to develop

these technologies and build an information stockpile on substitution and conservation is now.

The workshop considered four materials: chromium; cobalt;

tantalum and titanium. This was in accordance with the request

of the sponsors (see charge to workshop)

.

Sl-1
2

Chromium

The U. S. is a major consumer of chrome ore, and is dependent

for chromium on essentially a few foreign sources where supply

could be shut off with appalling speed (e.g. S. Africa, USSR,

Zimbabwe). Domestic ores are negligible. Sixty-two percent of

U. S. consumption is for metallurgical applications, and two

thirds of this is for corrosion-resistant steels, much of the

rest going into high-strength and high temperature alloys.

Obviously, this is a precarious position. For critical applications, in superalloys, chromium is vital. However, for less

critical applications, in the major field of use, namely corrosionresistant steels, there are possible substitutes; for example,

titanium, coated low- or no-chromium alloys, modified or new

alloy systems like 9CrlMo, or MnAlFe . A computer alloy design

system has been developed that could be used to design low- or

no-chromium systems for heat treatable steels to meet pre-established criteria.

In brief, chromium is vital for many uses but in many other

uses we can conserve or eliminate chromium, retaining it for the

vital applications. Accordingly, it appears highly desirable to

document and evaluate information on technology for substitution

and conservation and have this intelligence available for ready

use in an emergency situation. Likewise, it would be desirable

to develop and support research to expand the substitution information stockpile giving priority to those areas where there is

both urgent need and a reasonable probability of success.

As one of the workshop participants expressed it: "It is

difficult to overstate the importance of chromium as an alloy

addition and the economic disruption that would accompany an

interruption of supply. Dependence on chromium is so broad

economically that substitutes must be developed if the nation

is to realize political freedom of action."

Sl-2
3

Cobalt

Cobalt supply has some similarity to chromium and some differences. The similarity lies in that we are again heavily

dependent on foreign sources, some of dubious reliability. It

differs in that we have a few reliable sources and even prospect

of domestic supply, not to mention the ocean sea beds. But the

geopolitical situation and the supply/demand market have been

such that the price of cobalt in the last few years has risen

dramatically. So, unlike chromium, criticality of cobalt is not

so much a basic scarcity as it is a matter of economics. Now almost

one half of cobalt used in this country goes into superalloys, and

another total of about 30% into magnetic materials, and in cutting

and drilling tools as a bonding agent for cemented carbides.

For superalloys, substituting nickel and other elements for

cobalt is taking place, or conserving it through techniques such

as near-net shape processing. In magnets, replacement of cobalt

seems to be no problem; in fact, replacement materials (e.g. containing rare earths or iron-chrome combinations) may have advantages. Boronizing will produce hard, wear-resistant surfaces to

replace cobalt-bearing alloys. Various carbide coatings on cutting

tools extend their life, thus decreasing cobalt requirements. New

particle metallurgy technology has enabled the complete elimination

of cobalt in certain high speed tool steels.

Tantalum

The tantalum situation is different from that of either chromium or cobalt. The U. S. has no reserves, although it has some

low-grade resources that might some day come into use. So the U.S.

imports about 97% of its needs. However, a significant amount

comes from more comfortable sources: Australia, Canada, Brazil,

Thailand. On the other hand, when it comes to replacing tantalum

with something else, the picture is bleak. Two-thirds of our

tantalum goes into capacitors, to a major degree critical, as for

example in control systems for jet engines, and for this type of

critical application there is no substitute without paying a

penalty in performance or reliability.

Sl-3
4

About 17% goes into metal working machinery and in tools as

carbides and here we can conserve and substitute. Eight to ten

percent goes into aerospace structures and superalloys and for

these applications there appears at this time to be no outright

replacement, but there are opportunities for conservation; for

example, extended life turbine blades directionally solidified,

or single crystal blades, or near-net-shape processing, or new

kinds of alloys produced by rapid solidification techniques.

Due to demand exceeding supply, the price of tantalum has

increased dramatically in the last few years. This made it worthwhile to re-open marginal mines and also to begin to use marginal

tin slags (the other major source of tantalum). As a rsesult,

supply has recently increased to the degree that supply and demand

are currently in rough balance. If the price remains at its current

level of about $85/lb, supply is likely to be adequate for the near

future, so again economics is controlling a very sensitive supplydemand balance and it behooves us not to be smug about it. For

example, urgently needed tantalum for single-crystal turbine blades

(12% tantalum) could seriously disrupt this balance.

Titanium

The situation here is different than in the case of the other

three metals. There is no shortage of raw material, even in the

U. S. Facilities are the problem, like sponge-producing equipment,

or melting or forging equipment. The erratic demand picture for

titanium, ever since the industry started, has prevented the industry from becoming stabilized or having enough confidence in projected demand to invest the necessary heavy capital for expanded

and improved facilities, although steps in this direction are now

planned

.

The aerospace industry, strongly influenced by the Federal

Government action, has been the prime user of titanium, and therefore, the cause of its ups and downs in demands. Increased growth

of the non-aerospace industry is a stabilizing tendency. Yet, with-

;

out titanium, aircraft would be heavily penalized in terms of

weight increase; and weight increase today means not only a performance sacrifice but also an operating cost penalty due to the

high cost of fuel. It has been said that 1 lb of saving on a commercial airplane may be worth $300-$400.

SI4
5

Titanium's cost inhibits its greater usage but cost is expected to drop. So in the sense of usage, titanium is critical,

but not in the sense of raw material supply. There are possibilities for substitution and conservation: composites; new and

improved aluminum alloys using rapid solidification techniques;

powder metallurgy, precision casting, and other near-net-shape

processing. Titanium is also a potential substitute for other

materials, like corrosion-resistant stainless steels.

Technologies for Displacement

In discussing the four critical materials, reference was

made to the potential of new types of materials and new process

techniques that are emerging. Composites, particularly at the

present time the carbon/epoxy types in aerospace applications,

not only can save critical weight and provide superior performance

but can also serve as substitutes for titanium and for other

materials containing at least some of the above critical materials

In the same context, the increasing consideration of using composites in the automotive and other non-aerospace industries has

impressive materials implications for the future (incidentally,

conserving fuel due to decreased vehicle weight)

.

In the decade ahead, high temperature composites using metal

or ceramic fibers in metal or ceramic matrices should prove interesting and increasingly applicable and are examples of where research and development are currently needed to provide basic

understanding of behavior, improved material properties, and processing and design concepts adaptable to brittle or near-brittle

materials. In connection with the latter, monolithic ceramics,

especially silicon carbide and nitride, offer very interesting

possibilities particularly in selected elevated temperature

applications

.

Coatings and Surface Modification Systems

With respect to coatings and surface treatments, there are

so many operating techniques available that it appears that practically anything can be coated with anything to serve a predetermined objective. Thus a material lean in critical elements and

SI5
6

functionally suitable in every respect except resistance to a hostile environment can very likely be protected against that

environment

.

Surface treatments ranging from angstroms to an inch thick

on a noncritical metal or alloy can often provide the wear or

corrosion resistance of solid critical materials.

Coatings can also be used as thermal barriers to lower

metal operating temperatures thus permitting use of leaner

alloys in many cases for the same performance requirements.

Surface treatments that conserve expensive and/or critical

materials include cladding, hard facing, surface alloying, electron beam irradiation, sputtering, and thermal spraying.

Cladding, like coating, makes it possible for a relatively

small amount of a critical material to go a long way. Properly

applied materials can often provide all the advantages of a solid

critical alloy composition.

Hard facing is a form of weld overlay surfacing. Alloys used

generally fall into one of four classifications: cobalt base,

nickel base, iron base, and tungsten carbide composites. There

is considerable effort to reduce the cobalt content in wear resistant surface alloys.

Perhaps the greatest opportunity for the application of hard

facing technology to conserve critical materials is a design for

maintenance philosophy. Rather than attempt to design the entire

body of a component out of a highly alloyed strategic material,

opportunities exist to construct the part using less critical materials and then hard face the surface with a suitable alloy to

resist wear.

Surface alloying offers a significant opportunity for conserving critical metals such as chromium. Elements are utilized in the

most effective manner by placing them on the surface where they are

required for corrosion, oxidation, or wear resistance. Application

techniques include high temperature diffusion, selected surface

melting, and ion implantation.

Sl-6
7

Ion implantation involves a plasma of ions driven by an

electrical charge. The resultant surface alloy is in the range

of 500 to 3000 angstroms (50 to 300 rim) thick.

Laser alloying is generally in the development stage. It

offers good control, selected area treating, and limited heating

of the substrate. In laser glazing, a thin layer of the substrate is melted with an alloy addition and rapidly self-quenched

.

Wear resistant surfaces are also produced by pack or salt

bath boronizing. Metal carbides are formed by reaction or infusing

metals and carbon in the steel. Use of boronizing for the bearing

surfaces of journal bearing-type rock bit head sections has been a

successful replacement for cobalt base alloy applications.

Another Challenge: Better Use of What We Have

A strong point made in the workshop was that research should

be directed toward the development of material technologies that

utilize domestic and near-domestic metal resources to the fullest

extent

.

For example, manganese is of interest in the long term as a

resource in alloy systems utilizing aluminum to substitute for

chromium in stainless steels. The potential for abundant supplies

of manganese from ocean mining of nodules suggests a long-term

research support for use of manganese in alloy design.

Molybdenum has great potential for substitution for critical

metals. As was noted, chromium is widely used as a hardenability

addition for steels and irons, and molybdenum can play a valuable

substitution role in this application. Applications of vanadium

for heat treated steels offer possibilities.

In conventional superalloys, the contribution of tantalum to

high temperature creep resistance can be performed by a combination of columbium, titanium, and hafnium carbide strengthening,

plus molybdenum and tungsten solution strengthening. Tungsten is

now considered as a "safe" element to be used as a replacement

for critical elements.

S 1 - 7
8

Molybdenum as an alloying element in stainless steel offers

economically competitive substitutes for titanium in most of its

corrosion applications.

Nickel provides many opportunities for alloying use as an

alternate to chromium, cobalt and titanium should the availability

of these elements be seriously restricted. Considerable progress

has already been made in substituting nickel base alloys for those

containing large amounts of cobalt.

Stockpiling of Information on Substitution Technology

An important topic was considered in the concluding workshop

session: stockpiling of information on substitution technology.

The concept is to prepare a data base and bank of technical properties of potential substitutes including processing information

for critical materials that could be used to accelerate substitution

in an emergency. Several existing systems and information centers

were described as having the capability of storing, retrieving and

disseminating technical information; and what would be needed to

expand a system adequately was explored.

The basic concept itself was carefully examined in terms of

its advantages, problems, scope and cost. It was clear that a "substitution preparedness" system was highly desirable, but that

the development and selection of such a system should be approached

carefully, with proper planning, and preferably on an experimental

trial basis at first. As previously noted, the selection of

chromium for a pilot study would serve a most useful purpose.

A national materials substitution data base to be of broad use

should include information on manufacturing processes and design/

materials interactions. The development of such a data base would

be a major undertaking, but without such a starting point, national

response to material shortages would be at a disadvantage with little

available guidance. Stockpiling of critical materials has long been

considered and has been implemented to a degree. However, the workshop stated that it is also important to stockpile the information

needed on how to use alternate materials and that action should be

taken now to establish a Materials Substitution Information Data

Bank.

Sl-8
9

Suggestions For a Role of the Government

In spite of what is being done to prevent or alleviate shortages, there are causes for concern, as has been explained: either

a transient shortage disruptive of urgently needed production or a continuing shortage that could be disastrous, both cases of vital

concern to national security and industrial health. Awareness,

alertness, and preventive activites are necessary — and this means

activity and not rhetoric.

These activities are driven by the issues of availability,

cost, or performance. As brought out in the workshop, incentives

of cost reduction or product improvement or new markets have stimulated industry, as well as the Government, to do many things along

the lines of substitution, conservation, and technology development.

However, when it comes to timely availability, it seems advisable

that the Government play a leading role.

Some general deductions pertaining to the Government's role

are summarized below:

1. There must be a clear definition and appreciation at all levels

of the nature and magnitude of the problem, not in generalities,

but specific with respect to each potentially critical commodity.

2. There must be a long-term, related, comprehensive policy, an

• implementing plan, and suitable strategy and resources to go

with it.

3. Achievement of stockpile goals, in terms of both quantity

and quality, must be accelerated.

4. Where there is no realistic incentive for industry to invest

heavy capital in high-risk or long-term research and development which, however, shows promise of ultimately aiding availability, then support, or at least seed money, should be provided. Examples are basic research to understand the functional behavior of critical elements, as illustrated in current

work on cobalt; or the exploitation of RST; or computer design

of alloys to avoid critical metals.

5. As a preparedness measure, generic technology that cuts across

many industries and many types of applications should be supported, even though in some cases they cannot be immediately

related to an immediate specific mission or problem.

Sl-9
10

6. Action should be taken toward developing a plan for generating

and storing a substitution data base, taking into account the

many caveats expressed at this workshop, so that it could be

utilized as an aid in an emergency to minimize delay and

redundancy of effort. In this respect, the time, effort and

cost to bring a development from the laboratory to practical

fruition, with adequate data for designer confidence and manufacturing capability , with demonstration of reliability, should

by no means be underestimated.

7. Consideration should be given to establishing some type of

national advisory and/or coordinating group, specifically

related to critical materials issues, consisting of representatives from Government, industry, and academia, in a cooperative and non-adver sar ial climate.

8. Renewed efforts should be made to establish an early warning

capability for threatened shortages of critical materials or

threatened unusual commodity price increases, with a mechanism

for broadly disseminating such information to permit all sectors

to take appropriate protective or evasive action. With this

and other Government informational aids, industry itself, as is

most appropriate, should then be in a better position to make

commodity projections of a type and in a manner most applicable

to its own specific needs.

9. It is clear from this workshop that there are impressive technological developments, in being and on-coming with extensive

critical technical information not adequately known to those

who could use it to alleviate supply /demand problems. Assistance should be provided in collating, analyzing, and distributing such information and technology when not proprietary or

otherwise restricted.

SI- 10
11

Responsibilities of the Private Sector

With a continued program of cooperation, and with all the

technical talent that exists in this country, there is little

doubt that much can be done to reduce the threat of supply

shortages that could devastate the nation's security or industrial health.

The business sector should assume responsibility to maintain

an awareness of critical material requirements in new product and

process developments and in long term planning. Technical responses

should include research on substitution alternatives and development work in cooperation with customers and suppliers which focuses

on systems based on available metals and alloys with only small

additions of critical materials.

Also, work should be pushed to enhance the mechanical properties of less critical alloys to improve performance requirements.

Application of advanced materials and coating systems to reduce

the over-all need for critical metals should be studied.

Finally, it is important that information on critical materials issues and on work needed be discussed openly at all levels

within a company and especially at corporate levels where priority

assignments are made.

SI- 11
SUMMARY OF FINDINGS
Workshop Brainwriting Process

SUMMARY OF FINDINGS

Using the information obtained from the workshop participants in the

brainwriting exercise, forty findings were developed. These forty findings

are presented in rank order of agreement in Table I in their entirety.

The first twenty-eight findings which showed a high level of agreement are grouped according to topic below. Only an extract is used when the finding

is lengthy.

Technological Information - Displacement and Substitution of Materials

To reduce the use of critical metals, technological information must be

developed, organized, and applied. The findings show a desire for additional

information on alternative materials and their processing, and the development

of an information stockpile on substitution technology.

The findings showed a desire for improved organization of technological

information. Information useful primarily in an emergency could be organized

into a stockpile.

RANK

3 ... information needed for substitution of chromium ••• the substitute material for the component will have to be

a material which has already been qualified •••

6 Another extremely important part of the data required

for emergency substitution would be the corrosion

resistance in hostile environments.

12 Emergency substitution would require data on alloys

derived from reprocessed material of doubtful origin.

Thus, knowledge of the impurity efforts would be needed.

20 Current information systems do not often record the

properties of non-standard grades.

There are opportunities for conserving critical metals through the use of

coatings. However, additional information must be developed to take full

advantage of the opportunities.

RANK

5 Good opportunities exist for conserving large amounts

of critical materials through the use of coatings,

claddings, and various forms of surface alloying ••• there is reluctance to take the risk of putting these

coatings into active service in cases where failure

of the coatings could cause hazard •••or large

economic liability •••

SF1-1
8 There are incentives, both economic and technical, for

coating corrosion - or wear-resistant materials to

enhance their surface properties. What is needed

particularly is more work (research) to give confidence

that we can coat mild steel •••

16 Information concerning coatings that might be used to

lower chromium use in materials would be desirable.

25 One particularly promising coating is surface alloying

••• one problem is that properties necessary in the core material may be affected unpredictably , or may

actually be degraded ••• The lack of information concerning materials which could be used as substitutes for chromium bearing alloys was brought out in the findings.

RANK

17 Good data are severely limited for chromium-free

alloys which could be used as substitues under

demanding conditions.

23 There may be substitutes for chrome bearing materials

with acceptable mechanical properties, but information

about melting, casting, machining, joining, and heat

treating is needed ••• The removal of chromium from high temperature , corrosion resistant,

alloys is not possible based on current technological information.

RANK

22 ••• the high temperature corrosion and oxidation

resistance provided by chromium makes substitution

for it in these applications difficult ••• The use of composite materials in aircraft structures will indirectly

reduce the use of critical metals.

RANK

14 ••• organic matrix composites ••• will result in a weight reduction of about 20 percent in aircraft

which will allow for downsizing of engines and a decrease in the use of critical materials

Process Development to Conserve and Enhance Properties

The findings demonstrated the advantages associated with cleaner, higher

quality, powders which could be used to form near net shapes and reduce the

use of strategic raw materials needed to produce a component. Research should

be pursued to clarify the potential for rapid solidification technology to conserve critical metals.

SF1-2
RANK

9 Cleaner powders are essential for increased use of near net shape

production processes.

15 Gas atomization is one particularly promising RS

technology. Other methods may also have commercial

potential, for instance, some version of melt spinning.

19 One problem with powder technology has been reproducibility and quality control of the powder.

28 The increased alloying levels and homogeneity of RST

powder appear to be unusually attractive in disc

development -- particularly when coupled with near

net shape superplastic forming technology.

The employment of rapid solidification depends in part upon the development

of particular technological information.

RANK

7 ••• analysis needs to be performed to correlate particle

size to strength and toughness improvements, and to

establish the comparative advantage of RST to the traditional hot worked metals.

Composite materials offer opportunities for the displacement of critical

metals, given additional technological information.

RANK

21 ••• metal matrix composites may have the capability to

displace some superalloys containing Co and Cr. Metal

matrix composites is an area needing continued development.

27 ••• development is needed to raise the temperature

ceiling of polymeric materials for moderately

elevated temperature application.

Environmental factors may inhibit the development of processes to obtain

titanium from domestic sources of ilmenite.

RANK

24 ••• Domestic ilmenite (rather than foreign rutile) could

serve as a source of titanium in an emergency ••• attention needs to be paid to ferric chloride pollution.

Corporate Policy and Role of Government

Corporations are not likely to commit money and time to the development

of substitutes which might be used in a future emergency, if those currently

in use are technologically and economically satisfactory. Government support

is needed to develop stand-by information for emergency substitution.

RANK

11 It is difficult to justify large industrial R&D

expenditures on substitutes at times of ready availability and low cost of a critical material •••

SF1-3
development of information on emergency substitution

for, and displacement of, chromium will require

substantial funding from Government ••

•

13 The basic role of Government is to perform critical

basic research that may be too costly and/or too

risky for private industry alone (long range/high risk).

Market Development

Market development is the principal barrier to the stabilization of

titanium production which would avoid alternate shortages and gluts.

RANK

26 Expansion of the range of uses of titanium through

cost reduction, aggressive exploration of new markets, and possibly improved properties are the

most appropriate routes to ensure a more stable

supply of titanium • •

•

Economic Influences

Domestic resources, though they may be uneconomic, offer excellent

technological opportunities for reducing the use of critical metals.

RANK

1 There are a number of technical opportunities that

might be developed and expanded in order to utilize

domestically available elements such as nickel,

tungsten, vanadium, and molybdenum to substitute,

at least partially, for chromium, cobalt, tantalum,

and titanium.

Recent price increases for cobalt and tantalum have promoted a strong

substitution initiative and retarded expansion in their uses. This is

demonstrated by the four findings summarized below

RANK

2 The sharp rise in the price of cobalt has stimulated

its displacement in some high temperature and wear- resistant applications.

10 There is a wide spectrum of magnetic alloys where

substitution to reduce, or eliminate, the use of

cobalt is both technically and economically possible.

4 The high price of tantalum provides a strong driving

force for its displacement in certain applications.

18 Considering the small amount of tantalum which is

recycled now, and its price, opportunities to recycle more should be identified.

SF1-4
TABLE I

RANK ORDER OF FINDINGS ACCORDING TO LEVEL OF AGREEMENT

ITEM NUMBER RANK FINDINGS WITH LEVELS OF AGREEMENT BETWEEN STRONGLY AGREE AND AGREE

51.

8 .

58.

15.

46.

62.

39.

49.

42.

9.

3.

59.

72.

26 .

1 There are a number of technical opportunities that might be developed and expanded in order

to utilize domestically available elements such as nickel, tungsten, vanadium, and molybdenum

to substitute, at least partially, for chromium, cobalt, tantalum, and titanium.

2 The sharp rise in the price of cobalt has stimulated its displacement in some high temperature

and wear-resistant applications.

3 The information needed for substitution of chromium, as an example, would depend on the

warning time prior to the cut-off. If cut-off is immediate, the substitute material for the

component will have to be a material which has already been qualified for the application.

If information is available in advance, the effect of downgrading can be minimized.

4 The high price of tantalum provides a strong driving force for its displacement in certain

applications.

5 Good opportunities exist for conserving large amounts of critical materials through the use

of coatings, claddings, and various forms of surface alloying. Many such applications are

in use today and others are economically promising. There is reluctance to take the risk

of putting these coatings into active service in cases where failure of the coating could

cause hazard (e.g., possible jet engine failure) or large economic liability (e.g., possible

failure of valve seats in automobile engines). Uncertainty about long-term reliability

and lack of dependable inspection procedures for quality control to ensure long-term

reliability are impeding the introduction of coatings in some applications.

6 Another extremely important part of the data required for emergency substitution would be the corrosion resistance in hostile environments.

7 Highly dispersed precipitates and increased solubilities of alloying elements are definite

advantages of RST . However, further analysis needs to be performed to correlate particle

size to strength and toughness improvements, and to establish the comparative advantage of

RST to the traditional hot worked metals.

8 There are incentives, both economic and technical, for coating corrosion- or wear-resistant

materials to enhance their surface properties. What is needed particularly is more work

(research) to give confidence that we can coat mild steel or other nonresistant materials

and use these coated materials to displace the highly alloyed materials which require

critical materials. This should ultimately be economically advantageous in many applications.

9 Cleaner powders are essential for increased use of near net shape production processes.

10 There is a wide spectrum of magnetic alloys where substitution to reduce, or eliminate,

the use of cobalt is both technically and economically possible.

11 It is difficult to justify large industrial R&D expenditures on substitutes at times of ready availability and low cost of a critical material. It is also difficult to predict

if and when a material will become unavailable. In such instances development of information

on emergency substitution for, and displacement of, chromium will require substantial funding

from the Government. Corporations by themselves will not fund such work, nor give it the necessary priority to have the data available for use by anyone at some time in the future.

12 Emergency substitution would require data on alloys derived from reprocessed material of

doubtful origin. Thus, knowledge of the impurity effects would be needed.

13 The basic role of Government is to perform critical basic research that may be too costly

and/or too risky for private industry alone (long range/high risk).

14 Although organic matrix composites will not play a major role as replacements for high

temperature critical materials in aerospace in the 1 980 1 s , they are a new class of high

performance materials which will compete with the more conventional materials (e.g.,

aluminum, steel, titanium) in aerospace. Their use will result in a weight reduction of

about 20 percent in aircraft which will allow for downsizing of engines and a decrease in the use of critical materials (e.g., cobalt, tantalum) in aircraft engines in the 1980's.

SF1-5
37. 15 Gas atomization is one particularly promising RS technology. Other methods may also have

commercial potential, for instance, some version of melt spinning.

63. 16 Information concerning coatings that might be used to lower chromium use in materials would

be desirable.

60.

16.

40.

61.

28.

2 .

1 .

18.

47.

20 .

27.

36.

17 Good data are severely limited for chromium-free alloys which could be used as substitutes

under demanding conditions.

18 Considering the small amount of tantalum which is recycled now, and its price, opportunities

to recycle more should be identified.

19 One problem with powder technology has been reproducibility and quality control of the powder.

20 Current information systems do not often record the properties of non-standard grades.

21 Major technological obstacles in substitution for critical metals in high temperature

applications exist. Metal matrix composites have the potential for achieving good high

temperature performance. Therefore, metal matrix composites may have the capability to displace some superalloys containing Co and Cr. Metal matrix composites is an area needing

continued development.

22 Given current technological knowledge, the high temperature corrosion and oxidation

resistance provided by chromium makes substitution for it in these applications difficult,

if not impossible.

23 There may be substitutes for chrome bearing materials with acceptable mechanical properties,

but information about melting, casting, machining, joining, and heat treating is needed,

in addition to mechanical properties.

24 The concern about disruptions or potential disruptions of the availability of titanium

components in the United States is different from the concern with the other metals

considered at this workshop. Domestic ilmenite (rather than foreign rutile) could serve

as a source of titanium in an emergency, if pilot production is undertaken. However, to exploit ilmenite domestically, attention needs to be paid to ferric chloride pollution.

25 One particularly promising coating is surface alloying. It appears to offer a great variety

of coating capabilities without fear of spalling or edge effects. One problem is that

properties necessary in the core material may be affected unpredictably, or may actually

be degraded by the application method (higher temperatures).

26 Expansion of the range of uses of titanium through cost reduction, agressive exploration

of new markets, and possibly improved properties are the most appropriate routes to ensure

a more stable supply of titanium. There are technology options worth pursuing toward these

objectives.

27 Major technological obstacles to using composites as substitutes include elevated temperature

performance; both for moderately elevated temperatures (a few hundred degrees C) and high

temperatures (vicinity of 1000°C). Further development is needed to raise the temperature

ceiling of polymeric materials for moderately elevated temperature application.

23 The Increased alloying levels and homogeneity of RST powder appear to be unusually attractive

in disc alloy development--particularly when coupled with near net shape superplastic

forming technology.

FINDINGS WITH LEVELS OF AGREEMENT BETWEEN AGREE AND DISAGREE

30. 29 Quality control procedures of composite materials fabrication must be incorporated in the fabrication processes. Current NDE procedures are generally inapplicable to the inspection

of completed complex composite structures and components.

29. 30 While composite materials manufacturing processes are not considered prohibitively labor

intensive in the aerospace industry, they are currently sufficiently labor intensive to pose economic problems for application in the automotive and other non aerospace industries.

SF1-6
14.. 31 In the electronics industry, tantalum ranks third in degree of concern, behind cobalt

and platinum metals.

31. 32 There is a very large body of knowledge about the resistance of metal alloys to specific

and troublesome environments. There are good possibilities for using composites instead

of stainless and other corrosion resistant special alloys in such troublesome environments.

For example, polymer based composites with graphite or other reinforcements can replace

critical metals used in extremely corrosive environments, such as in chemical production

and in environmental and maritime service.

38. 33 Use of abundant materials such as A1 anf Fe in RST could reduce our vulnerability to foreign suppliers of Co and Cr, but achieving higher performance is probably an even greater reason for developing RST materials.

41 . 34 Improved testing procedures, especially NDE methods, will expand the use of near net shape

production processes.

65. 35 The ceramic technology offers long range potential for increased performance (e.g. in adiabatic diesels) and decreased dependence on critical metals.

64. 36 Chromium cannot be removed from nickel base superalloys currently used in hot turbine

applications on the basis of present information. It may be possible to use claddings to substitute for some of the chromium if adequate information were available.

21. 37 New alloys are needed which are tailored for specific uses. (Titanium)

48. 38 Chromi zed-coated sheet as a replacement for stainless steel failed commercially for economic

reasons only. Chromized sheet would serve as a substitute for stainless steel in many

applications and would conserve at least 50% of the chromium now required for stainless steel

19. 39 There is no current agreement as to which step-sponge production, melting, or mill shape

fabrication is the choke point causing shortages, or long lead times, for titanium

production.

13. 40 Of the four metals considered in this workshop, tantalum is likely to be the most critical

from the viewpoint of substitution. Its criticality may increase with the advent of single

crystal blades in jet engines.

SF1-7
SUMMARY OF RECOMMENDATIONS

R1
Workshop Brainwriting Process

SUMMARY OF RECOMMENDATIONS

Thirty-seven recommendations were developed using the information

obtained from the participants. These thirty-seven recommendations are presented in Table II in rank order of combined importance and

effectiveness in their entirety. Additional information obtained from

the evaluation is also presented in Table II. The first twenty-seven

recommendations which showed a high level of combined importance and

effectiveness are grouped according to topic below. Only an extract is

used when the recommendation is lengthy.

Stockpiling and Disseminating Technological Information for Displacement , Substitution, and Conservation of Critical Materials

Of the twenty-seven recommendations, ten were related to the need

for development, compilation, and dissemination of technological information on displacement, substitution, and conservation of critical metals.

The organization of information for use during an emergency was considered to be an important and effective action that should be taken.

RANK

1 The information stockpile should include as many alternate approaches as possible including substitution,

processing, recycling, and alternate sources.

2 Emergency substitution for cobalt in military jet

engines involves lengthy testing and qualfication

requirements. Back-up alloys should be prequalified

for use in emergencies,

3 A human stockpile of information should be organized

which could be employed immediately during an emergency.

5 Existing organizations that collect, stockpile, and

disseminate information could stockpile information

organized about each of the critical metals.

6 Priorities which would be invoked for allocating

critical metals in an emergency should be made known to

all concerned industries,

Rl-1
RANK

11 Comprehensive examination of the information developed

on uses and substitutions of critical metals, such as the NMAB report on chromium, should be conducted

periodically. ...

12 ... Government funding of special alloy development

and the building of a data base containing the

resulting information for use during an emergency.

Primary attention should be given to the most critical

oxidation and corrosion resistant applications. ...

20 To extend product life Government should promote long

term testing, ...and a program to understand failure in

terms of mechanism, ...for improving long-term

reliability of coated materials.

Dissemination of technological information must be encouraged if

reductions in the use of critical metals are to be achieved.

RANK

16 ...professional engineering organizations should

encourage universities to emphasize all materials,

not only metals, more heavily in Mechanical

Engineering curricula....

25 Technical meetings and workshops are needed periodically

to focus attention on opportunities for utilization

of domestically available materials in place of

critical imported materials.

Developing Technological Information for Displacement, Substitution,

and Conservation of Critical Metals

Two recommendations, involving studies to develop information

which would lead to a reduction in the use of chromium, follow.

RANK

10 In some cases, codes require a high chromium alloy when a lower chromium alloy or even a nonmetal would function

equally well. Alloy specifications codes should be

reevaluated

24 ...the U.S. Government may need to generate special

incentives. . .al loy systems could be developed based on manganese and aluminum, and iron and aluminum, which

could displace chromium based alloys.

Rl-2
Several types of basic research were recommended by the participants

as given below.

RANK

15 Studies in phase equilibrium relationships, structureproperty relationships, and solidification mechanism

should be stimulated through federal research support.

19 Basic research on the role which critical metals play

in alloys would provide information that would be

used in the normal materials displacement process...

guide effective substitution in an emergency.

22 Although cobalt is known to be an important constituent

of high temperature superalloys, its exact role as an alloying agent is uncertain. Additional R&D is needed

23 The exact role of tantalum as an alloying agent is

presently not well understood. Further R&D should be

directed to clarifying the role of tantlum....

Due to relative newness of the rapid solidification technology,

much basic technological information is needed.

RANK

27 Support mechanisms should be considered for design

trade-off, actual part evaluation, and test studies to

provide designer and producer confidence in the new

technol ogies ....

Process Development

Significant improvements in production processes for titanium are considered necessary, as brought out in the following two recommendations

.

RANK

9 ...development of energy efficient alternative

reduction processes ...that minimize the number of pro- cess steps and thereby provide more economical

titanium should be pursued.

23 ...titanium industry should be given a liberal tax

credit, or write offs of equipment and facilities, in

order to encourage investment in the electrowinning

process and other approaches

Improvements in the evaluation of composite parts is also needed.

It is the view of the participants that this development could be

implemented through private sector action.

Rl-3
RANK

4 Development of improved NDE procedures for composites

should be pursued for use in control of processing,

inspection after production and assembly, and inspection

after service.

Market Development

The development of more efficient production processes for titanium

is heavily dependent upon demand for the metal.

RANK

8 The titanium product shortage is not due to the lack

of installed capacity but to lack of long range

commitments Multi-year procurement commitments are needed

Economic Influences

The use of domestic materials which are not economic will occur

only if government is willing to offer economic incentives. The four

recommendations below demonstrate this view.

RANK

7 The Government should. . .encourage the development of

processes for the reclamation of critical metals

13 Full depreciation in three years or less should be

permitted for those fixed capital expenditures which

would lead to reclamation of critical metals.

17 Full depreciation in three years or less should be

permitted for those fixed capital expenditures which

would increase the availability of domestic metals or near domestic metals

21 The Government should see that adequate substitutes

are developed emphasizing domestic materials

In a more general sense, this view is borne out by the following

recommendations. These two recommendations are consistent with the

findings.

RANK

14 ...After certain processes with limited aerospace and

military application have been shown to be viable, the

Government may have to act as "champion" for continuing

development and pilot utilization.

Rl-4
RANK

18 The development of conservation options cannot be

justified by industry solely as a hedge against

possible periodic shortages. .. protection against future

potential shortages is a Government responsibility.

Rl-5
TABLE II

RANK ORDER OF RECOMMENDATIONS

RECOMMENDATIONS WITH COMBINED LEVELS

OF IMPORTANCE AND EFFECTIVENESS IN EXCESS OF THE MODERATE LEVEL

ITEM NUMBER

RANK BASED ON

to

o« oo

(_) LlJ z >

« —

•

I— J—

CrL O O UJ

Cl. Ll.

<_> Z

c

OLO

ccCJ«to

68. The information stockpile should include 1211 as many alternate approaches as possible

including substitution, processing, re- cycling, and alternate sources. It should

be tailored to the specific applications

and the properties required.

10.

66 .

35.

military

Emergency

jet

substitution

engines involves

for cobalt

lengthy

in 2156

testing and qualification requirements.

Back-up alloys should be prequalified

for use in emergencies, if they can provide "almost as good" performance.

A human stockpile of information should 3448 be organized which could be employed

immediately during an emergency.

Development

for composites

of improved

should be NDEpursued

procedures 4832

for

use in control of processing, inspection

after production and assembly, and

inspection after service.

70. Existing organizations that collect, 51329

stockpile, and disseminate information

could stockpile information organized

about each of the critical metals.

74. Priorities which would be invoked for 6 3 12 3 allocating critical metals in an emergency should be made known to all concerned industries, to encourage

rational planning for emergency

substitution.

57. The Government should, through some 7 6 6 32 incentive, encourage the development

of processes for the reclamation of

critical metals wherever possible.

Such technologies have been under

consideration for years, but most

are not economically attractive to industry without incentives.

24. The titanium product shortage is not 8 7 9 33 due to lack of installed capacity but

to lack of long range commitments on the part of users which would allow

better scheduling. Multi-year

procurement commitments are needed

and better and more stable forecasts

of needs.

23. The current costs of titanium and 9 5 15 12 titanium alloys are relatively high.

The development of energy efficient

alternative reduction processes (such

as direct reduction from chemical precursor to alloy powder) that minimize

the number of process steps and thereby

provide more economical titanium should

be pursued.

Rl-6

MEANS OF IMPLEMENTATION

IN ORDER OF FREQUENCY

OF SELECTION BY RESPONDENTS (SEE TABLE III FOR DEFINITION OF NUMBERS)

4 2 3 5 1

4 3 2 5 1

4 2 5 3 1

3 2 4 1 5

4 2 3 5 1

4 2 5 3 1

4 2 5 1 3

4 2 3 5 1

4 3 2 1 5
7. In some cases, codes require

a high 10 9 14 5 chromium alloy when a lower chromium

alloy or evena nonmetal would function

equally well. Alloy specifications

codes should be reevaluated by the

originating organization in light of current technology, to determine if high chromium steels are indeed needed

for the current applications. Appropriate

technological information should be provided to back up recorrmended modifications.

69. Comprehensive examination of the 11 17 7 4 information developed on uses and

substitutions of critical metals, such

as the NMAB report on chromium, should

be conducted periodically. High priority

should be given to this particular metal.

Useful information would include basic

property data, fabrication techniques and

requirements, and test results obtained

in service environments.

75. DOC recommendations should include 12 10 18 29 Government funding of special alloy

development and the building of

a data

base containing the resulting information

for use during an emergency. Primary

attention should be given to the most

critical oxidation and corrosion resistant

applications. Likewise, data should also

be organized for applications where

substitution and conservation are not economical under normal conditions, such

as with heat treated steels.

56. Full depreciation in three years or less should be permitted for those fixed

capital expenditures which would lead to reclamation of critical metals.

77. The Government is providing support for

critical metals conservation in aerospace materials, i.e., cobalt, through

established funding agencies. Large

savings of critical metals may be possible in commercial application,

but industry may be unable to support

such advanced programs. After certain

processes with limited aerospace and

military application have been shown

to be viable, the Government may have

to act as "champion" for continuing

development and pilot utilization.

Methods of providing support would

have to be established.

45. Studies in phase equilibrium relationships, and solidification mechanisms

should be stimulated through federal

research support.

34.

A big factor involved in achieving

greater use of composites in aircraft

is the education of designers to consider materials in the early stages

of design. To this end, professional

engineering organizations should encourage universities to emphasize all materials, not only metals, more heavily

in Mechanical Engineering curricula since

this is where most design engineers are educated.

13 20 7 34

14 15 10 27

15 19 11 23

16 24 16 19 4 2 3 1 5 4 2 3 5 1 4 5 2 3 1 4 2 5 3 1 4 5 2 3 1 4 2 5 3 1 3 2 4 1 5

Rl-7
55.

76.

67.

50.

Full depreciation in three years or 17 25 13 35 less should be permitted for those

fixed capital expenditures which would

increase the availability of domestic

metals or near domestic metals that are substitutes for critical metals.

The development of conservation options 18 21 19 13 cannot be justified by industry solely

as a hedge against possible periodic

shortages because the cost of industrial

R&D, and its implementation, must be justified by the return on investment

regardless of shortage considerations.

Investment in such options purely as a protection against future potential

shortages is a Government responsibility.

Basic research on the role which critical 19 26 17 16 metals play in alloys would provide

information that would be used in the normal materials displacement process where compound performance is a key part.

This information would also guide

effective substitution in an emergency.

To extend product life Government should 20 23 20 15 promote long term testing, (e.g., of uses

in selected Government applications), and

a program to understand failure in terms

of mechanisms, when it occurs, so that

useful guidance can be provided for

improving long-term reliability of coated

materials.

4 2 5 1 3

4 5 2 3 1

4 2 5 3 1

4 2 3 5 1

53.

11 .

17.

4 .

The Government should see that 21 14 23 31 45231

adequate substitutes are developed

emphasizing domestic materials

and available for use when needed.

Naturally the cost would be a factor

for commercial use, but strategic use

is not as dependent on cost.

Although cobalt is known to be an 22 16 22 22 4321 5 important constituent of high

temperature superalloys, its exact

role as an alloying agent is uncertain.

Additional R&D is needed for the study

of complex superalloy systems and tool steels in order that the development

of substitutes can proceed beyond a purely empirical point.

The exact role of tantalum as an 23 11 27 25 43251

alloying agent is presently not well understood. Further R&D should be directed to clarifying the role of

tantalum (structure versus properties)

in superalloys.

To ensure the development of process 24 12 29 14 45321

technology for applications of special

national interest, the U.S. Government

may need to generate special incentives,

including the funding of research and

dissemination of the results. New alloy

systems could be developed based on manganese and aluminum, and iron and

aluminum, which could displace chromium

based alloys.

Rl-8
52.

22 .

44.

Technical meetings and workshops are 25 29 21 7 needed periodically to focus attention

on opportunities for utilization of

domestically available materials in place of critical imported materials.

New large capacity electrowinning 26 18 26 30 plants employing modern technology

to reduce production costs are needed.

The titanium industry should be given

a liberal tax credit, or write offs

of equipment and facilities, in order

to encourage investment in the electrowinning process and other approaches

in view of potentially adverse market

conditions.

Support mechanisms should be considered 27 28 25 24 for design trade-off, actual part

evaluation, and test studies to provide

designer and producer confidence in the

new technologies and generate the data

needed for new designs.

3 4 2 1 5

4 2 3 5 1

4 3 5 1 2

RECOMMENDATIONS WITH COMBINED LEVELS

OF IMPORTANCE AND EFFECTIVENESS BELOW

THE MODERATE LEVEL

33. The more rapid and widespread use

of new and improved fibers and

polymeric matrix materials would

be accelerated by the orderly

compilation and analysis of their

physical and mechanical properties

over a broad range of temperatures

and environments.

32. The extension of usefulness of metal

matrix composites in elevated

temperature service conditions could

be a valuable contribution in relieving our dependence on chromium

and other critical materials. Research

and development in this field should be pursued.

73. Economic incentives for the displacement of some critical metals are weak.

Anti trust limitations on cooperative

research should be examined to determine

whether they can be waived to encourage

the development of substitutes for

critical metals such as chromium.

6. The cost and effort required to 31 22 33 18 42351

qualify a material which would

displace a critical material

(chromium) is a barrier to its

displacement. These procedures

should be evaluated with the

objective of reducing the cost

of qualification where possible

to encourage displacement.

28 31 24 10 3 4 2 5 1

29 27 32 11 4 3 2 5 1

30 30 28 28 4 5 2 3 1

Rl-9
43 . 4 2 3 5 1

12 .

71 .

25 .

54 .

5 .

A National Materials and Minerals

Policy should provide tax incentives

for investing in commercially-scaled

RS technologies.

Attention should be given to the development of non cobalt bonding

materials that would function in current machines with little or no change in operational procedure.

Mechanisms should be developed to induce the disclosure of proprietary

information on properties of substitutes for critical metals during

an emergency.

Better utilization of titanium can be realized through the use of improved

scrap reclamation.

Government procurement should be employed to increase the use of

domestic metals or near domestic

metals while decreasing the use

of critical metals in aerospace

equipment.

For a "technology stockpile" to

be effective in an emergency, a stockpile of capital equipment

to implement the technologies

may also be required. This is costly. Government financing,

or joint Government-private

sector involvement, would be required to create a real "technology stockpile."

32 32 34 37

33 34 31 20

34 33 35 21

35 35 30 17

36 36 36 36

37 37 37 26

3 4 12 5

4 5 2 3 1

3 4 12 5

4 2 5 3 1

4 5 2 3 1

Rl-10
PROCESS EMPLOYED TO DEVELOP

THE FINDINGS AND RECOMMENDATIONS

PRl

Workshop Brainwriting Process

PROCESS EMPLOYED TO DEVELOP THE FINDINGS AND RECOMMENDATIONS

Obtaining Information from the Workshop Participants

During the workshop information was obtained from the participants

employing a process referred to as brainwriting. In the application of

the process a question, written at the top of a sheet of paper, was given

to each participant at the end of each session (e.g. Session V-Composites)

.

The participant responded to the question in writing for ten minutes.

At the end of the ten minute period, participants exchanged their results.

Each participant then expanded upon the statements which he received.

After ten more minutes, the paper was returned to the originator and he

verified the statements which had been added. Then the papers were

collected by the person administering the brainwriting exercise.

Through this procedure, written responses to carefully developed

questions were obtained for each session during the workshop. To

illustrate the way in which the participants responded, the questions

and sample responses are given in Table III. The questions and responses

are grouped according to session. The responses show the breadth,

resolution, and quality of the information which we obtained from the

participants.

Candidate Findings and Recommendations

Following the workshop, the results of the brainwriting exercises

were analyzed. Through the analysis a set of findings and candidate

recommendations were developed for each session of the workshop. The

candidate recommendations and findings are presented in Table IV.

Evaluation of the Candidate Findings and Recommendations

The findings and candidate recommendations were sent to all 180

people who attended the workshop for evaluation on July 3, 1981.

PR1-1
Participants were asked to verify or refute the findings. They were asked

to evaluate the candidate recommendations for importance, effectiveness,

and means of implementation. They were asked to respond only to the

findings and recommendations with which they were familiar. The evaluation

sheet which was sent to the participants is shown in Table V.

Replies were received from 93 by July 17, the rating sheet having been

returned by 90 participants. The number of responses varied from about 50

to 75 for a particular finding, or recommendation. The results of the

verification of the findings by the respondents are tabulated in Table VI.

The results of the evaluation of the candidate recommendations by the

respondents are tabulated in Table VII.

Rank Ordering of the Findings

The tabulated findings in Table VI were weighted for agreement using

the scale given below

Strongly Agree - +10

Agree = + 5

Disagree - -10

This procedure yielded the rank order of the findings which is given in

Table I. Twenty-eight of the findings in Table I display levels of agreement between strongly agree and agree. The remaining twelve display levels

of agreement between agree and disagree.

Rank Ordering of the Recommendations

The results of the evaluation of the recommendations, tabulated in

Table VII, were weighted using the scales given below

1 . Of Major Importance - 10.0

2. Of Moderate Importance - 7.5

3. Of Limited Importance - 5.0

4. Of Minor Importance - 2.5

5. Of No Importance - 0.0

1 . Very Effective - 10.0

2. Moderately Effective * 7.5

3. Possibly Effective - 5.0

4. Probably not Effective * 2.5

5. Would not be Effective - 0.0

PR1-2
Of the 37 recommendations, 31 were considered to be at least moderately

important by the respondents. The remaining 6 were viewed as being at least

of limited importance. Of the 37 recommendations, 21 were considered to be

at least moderately effective. The other 16 were viewed as being at least

possibly effective. The recommendations are presented in order of combined

importance and effectiveness in Table II.

Other results drawn from the data given in Table VII are presented in

Table II. The five possible means of implementation given below were used

in evaluating the recommendations.

1. Will certainly be implemented through private action alone.

2. Would be implemented through private sector actions with

appropriate changes in public policy.

3. Could be implemented through private sector action alone.

4. Is unlikely to be implemented through private sector action

without appropriate changes in public policy.

5. Would not be implemented in the forseeable future through

private sector action even with appropriate changes in

public policy.

The fourth means of implementation given above, involving joint action by the

private and public sectors, was selected most frequently for 31 recommendations. The third means of implementation was selected most often by

respondents for the other 6 recommendations, as shown in Table II.

Respondents were given an opportunity to disagree with a recommendation,

if they felt that the recommendation was defective and preferred not to

evaluate it. Twenty-nine recommendations showed disagreement rates below 10%.

Three recommendations showed disagreement rates in excess of 20%, with five

between 10 and 20%. The rank order of disagreement is given in Table II.

PR1-3
SESSION I

TABLE III

CHROMIUM

QUESTIONS

1. In what cases is substitution for chromium currently most difficult technologically?

2. What are the most promising technological opportunities for

•economically favorable displacement of chromium (where technological and market opportunities

appear jointly favorable)?

•preparedness, or emergency, substitution for chromium?

3. What obstacles impede the otherwise economically favorable displacement of chromium through

technological development, and what future steps favoring these developments should be included

in the recommendations which the Department of Commerce makes to the Congress?

4. What obstacles impede preparation for emergency substitution through technological development,

and what future steps to improve emergency substitution should be included in the recommendations

which the Department of Commerce makes to Congress?

SAMPLE RESPONSES FROM 120 PARTICIPANTS

1.

Substitution for chromium is technologically most difficult in the high temperature alloys such

as used in gas turbine engines, etc. Replacing chromium for these applications is extremely

complex, since the alloy systems tend to be complex - often containing as many as ten or more different specified elemental additions - raising numerous possibilities for detrimental effects

of substitution, other than oxidation resistance. Coupled with this is the very demanding

"qualification procedures" any new alloys in these applications must undergo, to further

discourage substitution efforts.

* I agree with the above and in addition, areas requiring a high degree of corrosion resistance

appears to be a difficult area. Present technology on alloys with Cr reduced or eliminated

indicate that, in many cases, strength and oxidation resistance can be matched to current

stainless grades, but that corrosion resistance cannot, even with many alloying elements of

much greater expense. The corrosion resistance of such alloys in the broad range of oxidizing,

reducing mineral, & reducing organic acids, and chloride type environments appears to be the area requiring the most work.

1. The most obvious obstacle to Cr substitution is related to spontaneous formation of the protective oxide film at ambient and relatively low temperatures. To my knowledge, no one has been

able to replace Cr in this respect. Accordingly, where the beneficial role of Cr in providing

passivity is a requirement, Cr cannot be replaced. While there are combinations of alloying

elements that confer oxidation resistance at elevated temperatures such as A1 , Si, etc. as we have seen, none of them provide the opportunity for the total package of properties that Cr provides. They all fall short in one or more areas such as strength, sulfur resistance, etc. Accordingly, it will be necessary to tailor alloys to much more narrow markets and applications;

a factor that tends to complicate development and increase cost consideration.

* This is true but only pertains to essential uses of oxid. & corrosion resistant materials - what about not so critical applications. In that case investment in new technology becomes

the roadblock.

1. In hot, highly stressed, and critical components in jet engines. In most alloys now being used

the Cr is at the lower acceptable range that will produce the required properties. Cr has been

controlled very carefully in the past due to its tendency to form the embrittling sigma phase

during exposure to service temp. Generally speaking, the lower the Cr the less tendency to form sigma (assuming all other elements remain constant). Thus, Cr is already on the low side. To date, no other elements can satisfactorily replace Cr in these applications (alloys).

* The addition of 0.1 - 1.0% La has been found to improve oxidation resistance in superalloy.

Could that be a modification worth trying (may be patented).

2. The most favorable opportunities are in substitutes for stainless steels. Economically, at low

temperatures, because plastics, aluminum, coatings, and claddings will substitute for SS. Preparedness - there is a need for substitutes for 750-800°C applications, and substitutes can

be developed for this temperature range. It is more difficult at higher temperatures.

3. Industry has little incentive to develop substitutes for Cr because it is now available and the price has not fluctuated as the price for Cobalt. Therefore, the Government should take the lead in long-range research on chromium substitutes. There are many small deposites of Cr ore, but by the year 2000, the world will depend upon Southern Africa for chromium. Thus, the U.S. must have alternatives.

PR1-4
3. The main obstacle is substitution for chromium would be inertia or the fact that chromium has been economically available to stainless steel makers basically, and to the users of stainless

steel. I do not forsee extensive tampering with our free market system in peace time. We could

go as far as classifying chromium consumption into three categories. 1) essential 2) marginal

and 3) non essential

.

That way chromium consumers would have some warning as to whether their availability and access

to raw materials would suffer in an emergency. These classifications would have to be widely

published.

3. There is substantial lack of economic incentive to do this. It was emphasized over & over that

Cr j_s available and i_s cheap. The DOC should recommend some economic (monetary or tax) incentive

for those who will search for substitution developments even though they can still buy Cr readily

in the market.

4. The biggest obstacle is lack of incentive to invest the funds to prepare for substitute materials.

The present availability and relatively low price of chromium far outweigh "hypothetical" concerns

about future supply problems. Widespread government subsidies to establish the technology needed

for chromium substitution would be too expensive if the aim was to cover all possible uses. An alternate approach is for the government to prioritize chromium allocations and make industry

aware who would get chromium & who would not in a future emergency. The have-nots would be put

on notice to prepare for the future.

4. It appears difficult to justify the allocation of money and manpower required to prepare for emergency substitution in a number of major alloy categories on the basis of a "what if this

material is no longer available" supposition. To be truly ready for the worst case situations

for, e.g., Cr would require an enormous R&D effort to qualify the alternatives. Possibly,

political approaches to reducing or eliminating the threat of supply interruptions would be a more effective approach. Clearly the resources which would have been put into planning for

critical material shortages can be utilized in other areas of R&D on materials where they would

have greater benefits and not act primarily as insurance.

4. Today, unless there is a cost advantage to be shown, testing of "new" materials in the turbine

industry is almost impossible. In current production engines, it takes approximately $500,000 - $1 million dollars to test a new material. In the design of a new engine, cost becomes the

over-riding factor in material selection if both materials (new/current) are similar in properties. In fact, with the experience gained in previous engines, it would be very difficult

to select a new material without extensive testing (over and above that which is performed on the old material). It goes without saying that in times of shortages, the price of the "old"

material increases substantially and the "new" material becomes attractive, but, by then it is too late.

4. In addition to the allocation system, which was used for cobalt after the Zaire situation

disrupted supply, incentive for investment in long term R&D must become part of the national

materials policy. These incentives could take the form of greater-than otherwise available

tax credits for equipment modifications, capital expenditures for new plants, etc.

4. A major obstacle is the idea that U.S. weapon systems must be at forefront of technology when

in practice it has no real meaning. The Russians use proven equipment & more simple equipment.

Dept, of Commerce should recommend that Defense should analyze weapon systems for use of materials (critical) that cause problems if unavailable. We should try to design critical

stuff out.

* Indicates a response to the previous statement

PR1-5
SESSION II COBALT

QUESTIONS

1. In what case is substitution for cobalt currently most difficult technologically?

2. What are the most promising technological opportunities for

•economically favorable displacement of cobalt (where technological and market opportunities

appear jointly favorable)?

•preparedness, or emergency, substitution for cobalt?

3. What obstacles impede the otherwise economically favorable displacement of cobalt through

technological development, and what future steps favoring these developments should be included

in the recommendations which the Department of Commerce makes to the Congress?

4. What obstacles impede preparation for emergency substitution through technological development,

and what future steps to improve emergency substitution should be included in the recommendation

which the Department of Commerce makes to Congress?

SAMPLE RESPONSES FROM 43 PARTICIPANTS

1.

From the data given by the speakers it appears that the percentage of cobalt used in superalloys

has increased over the last several years. This means to me that due to the high cost of

cobalt, manufacturers in most industries are finding substitutes. The increased percentage of superalloy consumption of cobalt indicates, however, that no substitutes exist in this industry.

Since developing substitutes for superalloy uses of Co is the most difficult- technologically,

research like the COSAM program is justified.

1. Believe that the soft magnetic alloys represent a very difficult case. For instance Hiperca 50 or Permcudur type alloys (50 % Co) are critical for maintaining minimal weight/volume packages

in aircraft power generation systems. However these systems are present on alj_ military and

commercial aircraft. The desired properties for this application involve mechanical and

magnetic properties (especially high saturation magnetization). The criticallity of these

alloys to aircraft power generation systems should make them a high priority case for technical

substitution development efforts. I believe this particular case should be included in the upcoming DOC and DOD reports to congress.

2. Continued work on replacement of Co in magnetic alloys plus work to replace or substitute for

Co in superalloys. I do not agree that the near-net shape activities save any Co in the final

engines. The best near net shape will do is reduce the amount of Co in the chips and minimize

the recycle problems. To go to higher Co content to reduce the amount of superalloys processed

to engine parts misses the point as more Co actually ends up in the engines.

2. Substitution is ongoing, owing to a strong driving force (10 X increase in price). Most attention has been paid to superalloys since this is the largest (%) consumption - but it is occurring across the board. The users do not appear to be especially motiviated by concerns

about supply disruptions. Thus, I see no "contingency planning" for emergencies - only cost reduction drive, which will continue as long as the current price will prevail.

3. Substantial evidence now exists to indicate that reduction of cobalt by up to 50% in many alloys may be technically viable. The major obstacle, however, is (1) the time and resources required

to generate required design data for critical components such as disks and (2) the expense of

running extensive engine tests to verify the integrity of the component. In order to facilitate

rapid implementation in the event of a cobalt shortage, the DoD should implement programs to qualify leaner Co disk alloys. This step may also result in a reduction of the price of cobalt.

3.

Talks today indicate great success already achieved in replacing and reducing Co contents of

high speed steels (Crucible CPM REX alloys) and magnet alloys (Schlabach's talk). There is little need for government assistance or sponsorship in these areas. Government stimulation is needed in accelerating Co substitution in superalloys for gas turbine engine applications. It

is very costly and time consuming to prove out alloys applicability for engine uses.

3S4. I believe an important recommendation should be for the DOC to take strong measures to eliminate

the adversary relationships that now exist between government & industry. Anti-trust laws,

patents, protection of proprietary information are areas in need of complete overhaul and are far more important to accelerate progress in this country than any single technological development. More than anything else we need a climate that is conducive for the federal government

to work cooperatively with private industry.

* I say amen to the above. A good place to start would be with the mining and metal producing

industries.

PR1-6
SESSION III A COATINGS

QUESTIONS

1. What technological obstacles impede the otherwise economically favorable displacement of critical metals by coatings?

2. What currently economically unfavorable substitutions of coatings for critical metals are suf- ficiently promising for consideration for emergency substitution, such as a cutoff during a political embargo or wartime?

3. What specific approaches do you recommend to deal with these obstacles for inclusion in the

report of the Department of Commerce to the Congress?

SAMPLE RESPONSES FROM 26 PARTICIPANTS

1. Technological obstacles impeding the displacement of critical metals by coatings include the

lack of a universal method, or a group of universal techniques, for coating. Many of coatings

are line of sight, i.e. spray, and ion beam. Others include clip coating whose economics

restri ct usage. Coating technology does exist, however, usage appears limited.

2. Coatings & claddings offer ready (immediate) substitution of surface treatment for bulk use of

Cr, Co, etc. Cost of coatings & claddings obviously preclude such changes without other

pressures, such as embargoes. Some long range effort should be initiated to improve coating

technology.

2. Chromized-coated sheet as a replacement for 409 stainless steel failed commercially for economic

reasons only. Chromized sheet as a replacement for 409 could save significant amounts of chromium for many applications.

3. There must be an assured market with adequate profit for a number of years, to encourage the capital expenditure necessary to build a production line to supply chromized sheet.

3. A possible role for government would be in promoting long term testing (e.g. use in selected

government applications) combined with 1) a program to understand failure, when it occurs, in terms of mechanisms so that useful guidance can be provided for improving long-term reliability

and 2) development of improved inspection methods & standards for quality control.

PR1-7
SESSION III B RAPID SOLIDIFICATION AND NEAR NET SHAPE

QUESTIONS

1. What properties of rapidly solidized metals and near net shape products make them attractive as alternates to conventional alloys with imported sources?

2. What market sectors will benefit most over the next ten years from the conservation and substitution of critical metals utilizing rapid solidification and near net shape processing

technologies? Where are the major investment opportunities?

3. What are the major technical and institutional barriers or "choke points" in realizing the full technical potential from these processing technologies? For example:

•In what ways can computer-aided design, processing and manufacture and inspection further

enhance opportunities for conservation and substitution of critical metals utilizing

these processing technologies?

•In what ways will these processing technologies either enhance or limit the use of nondestructive evaluation methods for quality assurance?

4. What public policies, programs, or financial support are needed to assist producers, users, and

designers in developing confidence in these processing technologies? For example:

•How can alternate materials produced by these technologies be qualified for use without

jeopardizing the patent interests of producers, or suppliers?

SAMPLE RESPONSES FROM 45 PARTICIPANTS

1.

The tolerance of the realized HIP'd part must be close enough to the final shape such that the

reduction in machining costs off-sets the increase in cost of the part because of the high cost

of powder. The properties realized are usually equivalent to the conventional product when

using conventional alloys. Therefore, the net gain must be in machining. The assumption made

here is that "conventional" in the question refers to alloys that do not realize a special

property gain due to RSR techniques.

* The PM approach does not seem to discuss problems of dirt, defects from trapped gas & air and

other comtaminents

.

1. Fine grain size, homogeneity, small second phase size, increased solid solubility, decreased

machining costs, increased material utilization, increased ultrasonic inspection capability,

increased volume percent of second phases, usually higher strength and ductility, increased

toughness, better cutting tool performance, ability to replace certain elements such as W and

Co with Mo which is domestically available, etc.

2. High alloy content, high technology alloys which are used in very demanding applications.

Aerospace and gas turbine are probably the most obvious since the additional cost of the process

is not a high proportion of the total component cost. Rapid solidification appears to have the most possibilities but the furthest to go. Near net shape appears to have more immediate payoffs.

2. These technologies often involve powder production. Therefore compacting equipment, high temper- ature melting equipment, controlled atmosphere equipment will be needed. Development work on high volume production of economical very pure powders is needed. No one will commit to using

powdered metals unless they are assured of supplies at a reasonable price. Which comes first

powder or market?

Rapid solidification to produce strip & sheet also is a technology worth investigating because

of the high capital cost of current rolling mills.

3. Rapid solidification and near-net HIP shape technology offer good possibilities for reducing the use of critical materials. Some work still needs to be done.

a. CAD will be necessary for productive of as-HIP PM shapes on a routine basis.

b. Further improvement in properties needs to be achieved; particularly LCF.

c. Refractorless melting and processing needs to be developed to minimize possibility of

defects

.

d. Near-net sonic capability needs to be developed.

All areas will require continued government support to fully diffuse the PM as - HIP process.

4. These two processes should follow the normal road for new technology. I think that their

contribution to the critical materials issue is indirect at best and should not be overly

emphasized.

PR1-8
SESSION IV A TITANIUM

QUESTIONS

1. What specific technological developments might lead to significant reductions in the cost of

titanium components, and/or expansion in its non aerospace use?

2. What aspect of titanium production-reduction, melting, or mill shape fabrication - is most

likely to encounter future inadequacies which can result in significant shortages or price

increases?

3. What obstacles impede preparation for emergency substitution through technological development,

and what future steps to improve emergency substitution should be included in the reconmendations

which the Department of Commerce makes to Congress?

SAMPLE RESPONSES FROM 28 PARTICIPANTS

1,

Expansion of non-aerospace uses will be directly tied to methods to produce Ti and Ti alloys

much more economically. This means that methods to produce products directly from sponge must

be developed which will yield a satisfactory product. Advances in two significant areas are necessary.

a. high purity (low chloride and other contaminant) Ti powders must be made available

(economically), in order to promote powder fabrication. Other methods of producing Ti powder (e.g. D-H) may work out as well - important points are cost and purity!

b. homogenization (powder blending) processing technology must be developed (high

sophistication and low cost) to promote the use of P/M processing.

Summary - as long as we continue to use spherical Ti and Ti alloy powders ( expensive ) and

fabrication techniques that are expensive, we can never realize a significant non-aerospace

market.

1. Low cost production of Ti powder directly from ilmenite ore should lead to significant cost

reduction. Near net shape parts utilizing P.M technology (CIP) to minimize machining should

open doors for non aerospace application particularly in automotive engine parts such as connecting rods, wrist pins, valves.

1&2 The titanium technology, through production fabrication and alloy development, has been

essentially controled by rigid specifications for material that will be flown and in many cases

serve as rotating parts. In my own opinion this has precluded the use of resources to develop

lower-cost Ti alloys for use in less critical applications such as pump and valve components

for chemical plants. This situation is not likely to change in the near future, the aerospace

industry continuing to set the stage for titanium technology and technological advances. In the event chromium and/or stainless steel should increase significantly in cost, new titanium

technology might be forthcoming for corrosion resistant Ti alloy produced at low cost.

Mr. Burte may be pleased to know that the Bureau of Mines has scheduled research for the production of titanium alloy powder by co-reduction of the chlorides.

2. The supply of rutile could be cut off by international activities. It is possible that Timet

and other Ti producers would be almost wiped out of sponge for production of Ti tetrachloride.

Since we have large deposits of ilmenite in the U.S. I believe we should make strides to use

it. I understand that the Dow Process for production of Ti Cl 4 uses ilmenite effectively.

This could be incorporated and the D-H electralytic or Timet electrolytic sponge processes

should be exploited to cut costs. I think this is important since Titanium is the 9th most

abundant material found in the earth's crust and it could be used effectively in emergencies

of materials shortages.

3. Titanium should not be considered a critical material. The problem area with titanium,

fluctuating supply, is economic and materials utilization oriented and should be solved by

normal supply and demand techniques. I do think that recommending use of the stockpile to stabilize prices is a sound idea.

3. The major obstacle is cost. Neither we in industry, or the government, can afford to invent

substitutes. We must stabilize the source through expanded market. I think the major thing

the government and congress must do is not commit itself to a major program lightly, but follow

through with it, or cancel it. They must have an alternate plan for subsidizing the expenditures, building the stockpile, etc.

PR1-9
SESSION IV A TANTALUM

QUESTIONS

1. Of the eight elements dealt with specifically in this workshop (chromium, cobalt, titanium,

tantalum, molybdenum, nickel, vanadium, tungsten), where would you rank tantalum as a metal

critical

•To all industry?

•To the defense industry?

•To your industry? (specify industry)

(One is most critical, eight is least critical)

2. If manganese, the platinum group metals, and tin were added to this list, what would your

ranking be?

3. What obstacles impede preparation for emergency substitution through technological development,

and what future steps to improve emergency substitution should be included in the recommendations which the Department of Commerce makes to Congress?

RESPONSES FROM 23 PARTICIPANTS TO QUESTIONS 1 & 2

#1 #2 #3 #4 #5 #6 #7 #8 #9 #10

1. Industry 4 2 2 2

- - 2 1 - -

Defense 6 3 3 2

- 1 - - - -

Your Industry5 4

- - 1 1 - - - -

2. Industry 3 2 2 1 2

- 1 - - -

Defense 4 4 1 1 - 1 - - - -

Your Industry

4 2 1 - - 1 - - - -

SAMPLE RESPONSES FROM 23 PARTICIPANTS

1. Ta and Ti are candidates for the most critical materials in the gas turbine industry. Un- availability of Ti would have the most serious impact since the compressor sections of most

gas turbines are Ti base. Cutbacks in Ta would be significant, however, and Ta free superalloys

would mean lower performance (TSFC) and/or higher maintenance costs.

3. There seems to be a variety of opinions as to the effect of Ta on properties and to the reasons behind these variations. Certainly, the Ta effect will vary depending on the alloy (content of

all alloying elements). What is needed is some good baseline data on the role of Ta. At that

point, we would be prepared to take appropriate steps to attack the problem. In the meantime,

we ought to determine the role of Ta (structure vs properties) in superalloys.

3. Electronics applications has generally dictated extremely high purity Ta for best capacitance

and therefore restricting efficient recycling of Ta scrap (e.g. that with slight quantity of

Mo, or W). Perhaps it might be of some interest to review data and attempt development of

electronics requiring less pure Ta.

PR1-10
SESSION IV B DOMESTIC METALS

QUESTIONS

1. Should the government take an active role in encouraging the use of domestic or near domestic

metals as substitutes for critical metals?

2. Should the role of government be:

a) limited to basic research?

b) both basic research and development of new products?

c) to carry new products through field demonstration?

d) to encourage commercial development of substitutes for critical metals even if not presently economically justified?

3.

Should government action:

a) be limited to materials affecting national security?

b) cover both strategic and general commercial products?

c) be different for strategic and general commercial applications?

4. What steps to encourage the substitution of alloys using domestic or near domestic materials for

those using critical metals should be included in the recommendations which the Department of Commerce makes to the Congress?

5. What role should the technical societies play to encourage the use of domestic or near domestic

metal s?

SAMPLE RESPONSES FROM 34 PARTICIPANTS

1.

Twenty of the thirty four respondents answered this question positively, two negatively, three

introduced caveats, and nine did not deal with this question.

1. Only if private sector participates voluntarily, projects are long-term, incentives are designed

to expire on a certain date, or project proves economic or uneconomic by the certain date.

2. I think government role should be limited to basic research in so far as general usage products

are concerned. Development of substitutions will depend entirely on economics.

With respect to materials (alloys) used in national security applications superalloys etc.. Government laboratories and research grants should be focused on the development of new materials that conserve critical materials.

3. At present government action has to be restricted to conservation and/or substitution of

materials affecting national security. The economic forces will take care of the commercial

sector. Government action should be two fold - a) encouragement of conservation through

directives to companies involved in government contract supply to institute a conservation

approach to the selection of materials involving critical materials (e.g. use of aluminum

alloys in some corrosive environments instead of stainless steel); b) finance the basic

research of alloy replacement rather than short term advantages of one element at a time to improve only a single metallurgical property.

3. Government action should be restricted to materials affecting national security. Government

should supply guidelines for strategic materials used commercially. Supply and demand laws

will restrict commercial requirements adequately. Some government funds should be spent in the commercial area to encourage reclamation of strategic elements to assure adequate supply.

4. A structure of beneficial tax treatment of expenses related to demonstration and implementation

of new materials of reduced critical metal content and increased domestic or near domestic

metal content, particularly with regard to qualification expenses.

4&5 The Tech Societies & Government had better get together and decide on the running rules

(philosophy) to be used as a guide in formulating a policy and consequent programs. Programs

aimed individually can range from partially effective, overall, to counterproductive in the

"Big Picture."

PR1-11
SESSION V COMPOSITES

QUESTIONS

1. What technological obstacles impede the otherwise economically favorable substitution of critical metals by advanced engineering composite materials, such as graphite/resin,

kevlar/resin, carbon/carbon, and carbon/aluminum, as examples?

2. What currently economically unfavorable examples of substitutions of critical metals by

composites are sufficiently promising technically so that these uses can be pursued, should

there be an emergency, such as the cutoff of critical metals during a political embargo or wartime?

3. What specific approaches do you recommend to deal with these technical obstacles so that these

approaches can be included in the report that the Department of Commerce will submit to the

Congress in October?

4. Some people believe that the most important factor inhibiting more rapid penetration of

composite structures into the aerospace industry is a lack of broad industry experience with

advanced composites. Because of this lack of industry experience, industry's lack of con- fidence in composites for use in primary aircraft structures is understandable. What actions,

on a priority basis, should be taken in the next few years to improve that confidence level

in composites in order to accelerate their use in the aerospace industry in the 1 980 1 s and allow for lower costs as volume of use increases?

Please answer any one question about which you are most knowledgeable. Also, questions 1, 2 and

3 can be answered as a group of related questions.

SAMPLE RESPONSES FROM 65 PARTICIPANTS

1.

I feel that composites should replace metallic materials only where there is an economic

driving force. The nature of composites only permit them to be substituted for materials

which are not necessarily "critical" materials i.e. aluminum & titanium. Our most critical

materials are Cr & Co and there is no potential for composites to replace these materials.

Composites will realize the share of the market they deserve on their own merits and force

feeding of these materials by Uncle Sam is not warranted.

1. A major technological obstacle is investment in capital equipment for manufacturing that cannot

be converted to manufacture of composite structures i.e. forming presses, metal machining

tools, etc.

1

.

a. Obstacles are scale size of plant capacity to produce composite materials in large quantities

but this reluctance is based on an unsure assessment of the demand for the product, i.e. the chicken & egg circularity.

b. Current production work is too labor intensive; lack of sufficient automation in the production

process.

c. Quality control is difficult because it involves too many intermediate materials & supplies.

This makes certification more difficult.

2. The use of composites in primary airframe structures.

3. Resins need to be developed which are fast curing, low cost, moisture resistant, etc. Carbon/carbon composites need improved densification techniques. All composites need extensive

materials with low labor costs using relatively simple processing methods & equipment.

Quality assurance testing and control techniques must be developed which are part of the manufacturing process and which are simple, fast and reliable.

3. Certainly many automotive applications would appear to be currently favorable, but uneconomical.

To help accelerate these applications, more rapid tax writeoffs for installation of new mfg.

equipment appears to be in order. Perhaps the industry could select specific parts for use in primary aircraft structures for demonstration so that experience could be gained. It looks

like an industry-government cooperative effort in this direction will be required.

4. I don't agree with the premise stated in the 1st sentence. Composites are being introduced

into military aircraft much more rapidly than has been the case with most metal alloys in the

past. No additional impetus has to be provided to accelerate their use - high fuel costs in the case of commercial aircraft and demands for high performance in military aircraft are sufficient driving forces in themselves to encourage rapid conversion to composites.

PR1-12
SESSION VI INFORMATION

QUESTIONS

1. In the event of a total chromium cutoff, what information would you need to make an emergency

substitution in your products?

2. Is this information currently available? Is it accessible?

3. What would be your concept of an information system to provide data for substitution and

conservation in an emergency cutoff of supply?

SAMPLE RESPONSES FROM 44 PARTICIPANTS

Each of the first three sets of responses were provided by an individual participant.

1.

None. We have completed our alloy steel (Cr-free) test program.

2 .

3. I cannot imagine one that could be used without an evaluation procedure by each user; therefore

data must include service use data and processing details.

1. The categories of materials affected include:

a) low alloysteels for shafts, bearings

b) stainless steels (300, 400 series)

c) superalloy blades, vanes, disks, sheet alloys

Information required would be of the nature of

a) alternate elemental additions to give equal hardenability

b) design info (general) on Fe-Al-Mn, etc.

c) corrosion resistant coatings with improved durability

2. Category a data is available & accessible; other data may exist in part, but they represent

areas where substitution/replacement is simply not practical. What is really needed is the extent of reallocation possible to divert Cr away from cosmetic applications of stainless steels

to defense-related superalloys.

3. Existing system adequate.

1. Assume that there would be a priority system initiated under government control (as in World

War II and Korea). We would need to know as soon as possible the priority position for stainless steels relative to our particular usage. This would afford time to redesign and modify

existing components.

2. No, yes.

3. I believe that permitted freedom of action, and minimizing the bureaucracy, emergency substitutions could be implemented without too much difficulty with the knowledge and talent already

available. Provided we don't elect the route of becoming totally philosophical and make the same mistake of the ancient Athenians.

The following responses were provided by individual participants.

1. I would like the following info in any cutoff.

a) Eliminate/avoid confustion

b) Careful Government response and directives with pre warning of

1) what is magnitude and direction of allocations military U.S. Consumer, U.S. industrial

2) what is purity of any large governmental/industrial stockpile and allocation of

distribution

3) whether price controls (temporary I hope) would have to be imposed over short term

and long term.

3. No comment on chromium but a final thought is that if a stockpile of substitutional technology

is established then apart from helping substitute alternate materials it would be of considerable

help in improving the productivity of the country.

PR1-13
TABLE IV

FINDINGS AND RECOMMENDATIONS

The findings and recommendations given below are not intended to be exhaustive. They have been drawn almost entirely from the results of the brainwriting exercises. Consequently, important points made in the papers will not appear among the findings and recommendations.

The terms displacement and emergency substitution which are used in these statements have the following

meanings. Displacement occurs when technological and economic factors dictate the exchange of one material

for another. Emergency substitution occurs when one material is exchanged for another as a result of a shortage

caused by geopolitical factors, although the exchange is unfavorable technologically and economically.

To simplify your evaluation of the findings and recommendations, they are organized according to the topic

of each session held during the workshop. In addition, some of the findings and recommendations have been combined

into a general category. Separation according to topic will permit you to quickly identify those topics which

you wish to evaluate, and also those which you do not wish to evaluate. We prefer that you evaluate all of the findings and recommendations within a particular topic (e.g. titanium), though we do not insist that you do so. The evaluation procedure is explained on the rating form.

CHROMIUM

Findings

1. There may be substitutes for chrome bearing materials with acceptable mechanical properties, but infor- mation about melting, casting, working, machining, joining, and heat treating is needed, in addition to mechanical properties.

2. Given current technological knowledge, the high temperature corrosion and oxidation resistance provided by

by chromium makes substitution for it in these applications difficult, if not impossible.

3. It is difficult to justify large industrial R&D expenditures on substitutes at times of ready availability

and low cost of a critical material. It is also difficult to predict if and when a material will become unavailable. In such instances development of information on emergency substitution for, and displacement

of, chromium will require substantial funding from the Government. Corporations by themselves will not

fund such work, nor give it the necessary priority to have the data available for use by anyone at some time in the future.

Recommendations

4. To ensure the development of process technology for applications of special national interest, the U.S. Government may need to generate special incentives, including the funding of research and dissemination

of the results. New alloy systems could be developed based on manganese and aluminum, and iron and aluminum, which could displace chromiun based alloys.

5. For a "technology stockpile" to be effective in an emergency, a stockpile of capital equipment to implement

the technologies may also be required. This is costly. Government financing, or joint Government-private

sector involvement, would be required to create a real "technology stockpile."

6. The cost and effort required to qualify a material which would displace a critical material (chromium) is a barrier to its displacement. These procedures should be evaluated with the objective of reducing the cost

of qualification where possible to encourage displacement.

7. In some cases, codes require a high chromium alloy when a lower chromium alloy or even a nonmetal would

function equally well. Alloy specifications codes should be reevaluated by the originating organization

in light of current technology, to determine if high chromium steels are indeed needed for the current

applications. Appropriate technological information should be provided to back up recommended modifications.

COBALT

Findings

8. The sharp rise in the price of cobalt has stimulated its displacement in some high temperature and wear- resistant applications.

9. There is a wide spectrum of magnetic alloys where substitution to reduce, or eliminate, the use of cobalt

is both technically and economically possible.

Recommendati ons

10. Emergency substitution for cobalt in military jet engines involves lengthy testing and qualification requirements. Back-up alloys should be prequalified for use in emergencies, if they can provide "almost as good"

performance.

11. Although cobalt is known to be an important constituent of high temperature superalloys, its exact role as an alloying agent is uncertain. Additional R&D is needed for the study of complex superalloy systems and

tool steels in order that the development of substitutes can proceed beyond a purely empirical point.

12. Attention should be given to the development of non cobalt bonding materials that would function in current machines with little or no change in operational procedure.

TANTALUM

Findings

13. Of the four metals considered in this workshop, tantalum is likely to be the most critical from the viewpoint of substitution. Its criticality may increase with the advent of single crystal blades in jet engines.

14. In the electronics industry, tantalum ranks third in degree of concern, behind cobalt and platinum metals.

15. The high price of tantalum provides a strong driving force for its displacement in certain applications.

16. Considering the small amount of tantalum which is recycled now, and its price, opportunities to recycle more should be indentified. PR1-14
Recommendati ons

17. The exact role of tantalum as an alloying agent is presently not well understood. Further R&D should be directed to clarifying the role of tantalum (structure versus properties) in superalloys.

TITANIUM

Findings

18. The concern about disruptions or potential disruptions of the availability of titanium components in the United States is different from the concern with the other metals considered at this workshop. Domestic

ilmenite (rather than foreign rutile) could serve as a source of titanium in an emergency, if pilot production

is undertaken. However, to exploit ilmenite domestically, attention needs to be paid to ferric chloride

pollution.

19. There is no current agreement as to which step-sponge production, melting, or mill shape fabrication is the choke point causing shortages, or long lead times, for titanium production.

20. Expansion of the range of uses of titanium through cost reduction, agressive exploration of new markets,

and possibly improved properties are the most appropriate routes to ensure a more stable supply of titanium. There are technological options worth pursuing toward these objectives.

21. New alloys are needed which are tailored for specific uses.

Recommendati ons

22. New large capacity electrowinning plants employing modern technology to reduce production costs are needed.

The titanium industry should be given a liberal tax credit, or write offs of equipment and facilities, in order to encourage investment in the electrowinning process and other approaches in view of potentially

adverse market conditions.

23. The current costs of titanium and titanium alloys are relatively high. The development of energy efficient

alternative reduction processes (such as direct reduction from chemical precursor to alloy powder) that minimize the number of process steps and thereby provide more economical titanium should be pursued.

24. The titanium product shortage is not due to lack of installed capacity but to lack of long range commitments

on the part of users which would allow better scheduling. Multi-year procurement commitments are needed

and better and more stable forecasts of needs.

25. Better utilization of titanium can be realized through the use of improved scrap reclamation.

COMPOSITES

7 lndings

26. Although organic matrix composites will not play a major role as replacements for high temperature critical materials in aerospace in the 1980's, they are a new class of high performance materials which will compete

with the more conventional materials (e.g., aluminum, steel, titanium) in aerospace. Their use will result

in a weight reduction of about 20 percent in aircraft which will allow for downsizing of engines and a decrease in the use of critical materials (e.g., cobalt, tantalum) in aircraft engines in the 1980's.

27. Major technological obstacles to using composites as substitutes include elevated temperature performance;

both for moderately elevated temperatures (a few hundred degrees C) and high temperatures (vicinity of 1000°C). Further development is needed to raise the temperature ceiling of polymeric materials for moderately elevated

temperature application.

28.. Major technological obstacles in substitution for critical metals in high temperature applications exist.

Metal matrix composites have the potential for achieving good high temperature performance. Therefore,

metal matrix composites may have the capability to displace some superalloys containing Co and Cr. Metal matrix composites is an area needing continued development.

29. While composite materials manufacturing processes are not considered prohibitively labor intensive in the aerospace industry, they are currently sufficiently labor intensive to pose economic problems for application

in the automotive and other non aerospace industries.

30. Quality control procedures for composite materials fabrication must be incorporated in the fabrication

processes. Current NDE procedures are generally inapplicable to the inspection of completed complex composite

structures and components.

31. There is a very large body of knowledge about the resistance of metal alloys to specific and troublesome

environments. There are good possibilities for using composites instead of stainless and other corrosion

resistant special alloys in such troublesome environments. For example, polymer based composites with

graphite or other reinforcements can replace critical metals used in extremely corrosive environments,

such as in chemical production and in environmental and maritime service.

Recommendations

32. The extension of usefulness of metal matrix composites in elevated temperature service conditions could

be a valuable contribution in relieving our dependence on chromium and other critical materials. Research

and development in this field should be pursued.

33. The more rapid and widespread use of new and improved fibers and polymeric matrix materials would be accelerated

by the orderly compilation and analysis of their physical and mechanical properties over a broad range of temperatures and environments.

34. A big factor involved in achieving greater use of composites in aircraft is the education of designers to consider materials in the early stages of design. To this end, professional engineering organizations should encourage universities to emphasize all materials, not only metals, more heavily in Mechanical Engineering

curricula since this is where most design engineers are educated.

35. Development of improved NDE procedures for composites should be pursued for use in control of processing,

inspection after production and assembly, and inspection after service.

PR1-15
RAPID SOLIDIFICATION TECHNOLOGIES

Findings

36. The increased alloying levels and homogeneity of RST powder appear to be unusually attractive in disc alloy

development- -parti cul arly when coupled with near net shape superplastic forming technology.

37. Gas atomization is one particularly promising RS technology. Other methods may also have commercial potential,

for instance, some version of melt spinning.

38. Use of abundant materials such as A1 and Fe in RST could reduce our vulnerability to foreign suppliers

of Co and Cr, but achieving higher performance is probably an even greater reason for developing RST materials.

39. Highly dispersed precipitates and increased solubilities of alloying elements are definite advantages of

RST. However, further analysis needs to be performed to correlate particle size to strength and toughness

improvements, and to establish the comparative advantage of RST to the traditional hot worked metals.

40. One problem with powder technology has been reproducibility and quality control of the powder.

41. Improved testing procedures, especially NDE methods, will expand the use of near net shape production processes.

42. Cleaner powders are essential for increased use of near net shape production processes.

Recommendations

43. A National Materials and Minerals Policy should provide tax incentives for investing in commercially-scaled

RS technologies.

44. Support mechanisms should be considered for design trade-off, actual part evaluation, and test studies to provide designer and producer confidence in the new technologies and generate the data needed for new designs.

45. Studies in phase equilibrium relationships, structure-property relationships, and solidification mechanisms

should be stimulated through federal research support.

COATINGS

Findings

46. Good opportunities exist for conserving large amounts of critical materials through the use of coatings,

claddings, and various forms of surface alloying. Many such applications are in use today and others are economically promising. There is reluctance to take the risk of putting these coatings into active service

in cases where failure of the coating could cause hazard (e.g., possible jet engine failure) or large economic

liability (e.g., possible failure of valve seats in automobile engines). Uncertainty about long-term reliability

and lack of dependable inspection procedures for quality control to ensure long-term reliability are impeding

the introduction of coatings in some applications.

47. One particularly promising coating is surface alloying. It appears to offer a great variety of coating

capabilities without fear of spalling or edge effects. One problem is that properties necessary in the core material may be affected unpredictably, or may actually be degraded by the application method (high- er temperatures).

48. Chromized-coated sheet as a replacement for stainless steel failed commercially for economic reasons only . Chromized sheet would serve as a substitute for stainless steel in many applications and would conserve at least 50% of the chromium now required for stainless steel.

49. There are incentives, both economic and technical, for coating corrosion- or wear-resistant materials to enhance their surface properties. What is needed particularly is more work (research) to give confidence

that we can coat mild steel or other nonresistant materials and use these coated materials to displace the highly alloyed materials which require critical materials. This should ultimately be economically advantageous

in many applications.

Recommendati ons

50. To extend product life Government should promote long term testing, (e.g., of uses in selected Government

applications), and a program to understand failure in terms of mechanisms, when it occurs, so that useful guidance can be provided for improving long-term reliability of coated materials.

DOMESTIC AND NEAR DOMESTIC MATERIALS

Finding

51. There are a number of technical opportunities that might be developed and expanded in order to utilize domestically

available elements such an nickel, tungsten, vanadium, and molybdenum to substitute, at least partially, for chromium, cobalt, tantalum, and titanium.

Recommendations

52. Technical meetings and workshops are needed periodically to focus attention on opportunities for utilization

of domestically available materials in place of critical imported materials.

53. The Government should see that adequate substitutes are developed emphasizing domestic materials and available

for use when needed. Naturally the cost would be a factor for commercial use, but strategic use is not as dependent on cost.

54. Government procurement should be employed to increase the use of domestic metals or near domestic metals while decreasing the use of critical metals in aerospace equipment.

55. Full depreciation in three years or less should be permitted for those fixed capital expenditures which

would increase the availability of domestic metals or near domestic metals that are substitutes for critical metals.

PR1-16
56. Full depreciation in three years or less should be permitted for those fixed capital expenditures which

would lead to reclamation of critical metals.

57. The Government should, through some incentive, encourage the development of processes for the reclamation

of critical metals wherever possible. Such technologies have been under consideration for years, but most

are not economically attractive to industry without incentives.

INFORMATION STOCKPILE (SUBSTITUTION PREPAREDNESS)

Findings

58. The information needed for substitution of chromium, as an example, would depend on the warning time prior

to the cut-off. If cut-off is inmediate, the substitute material for the component will have to be a material which has already been qualified for the application. If information is available in advance, the effect

of downgrading can be minimized.

59. Emergency substitution would require data on alloys derived from reprocessed material of doubtful origin.

Thus, knowledge of the impurity effects would be needed.

60. Good data are severely limited for chromium-free alloys which could be used as substitutes under demanding

conditions.

61. Current information systems do not often record the properties of non-standard grades.

62. Another extremely important part of the data required for emergency substitution would be the corrosion

resistance in hostile environments.

63. Information concerning coatings that might be used to lower chromium use in materials would be desirable.

64. Chromium cannot be removed from nickel base superalloys currently used in hot turbine applications on the basis of present information. It may be possible to use claddings to substitute for some of the chromium

if adequate information were available.

65. The ceramic technology offers long range potential for increased performance (e.g. in adiabatic diesels)

and decreased dependence on critical metals.

Recommendation s

66. A human stockpile of information should be organized which could be employed immediately during an emergency.

67. Basic research on the role which critical metals play in alloys would provide information that would be used in the normal materials displacement process where compound performance is a key part. This information

would also guide effective substitution in an emergency.

58. The information stockpile should include as many alternate approaches as possible including substitution,

processing, recycling, and alternate sources. It should be tailored to the specific applications and the properties required.

69. Comprehensive examination of the information developed on uses and substitutions of critical metals, such

as the NMAB report on chromium, should be conducted periodically. High priority should be given to this particular metal. Useful information would include basic property data, fabrication techniques and requirements, and test results obtained in service environments.

70. Existing organizations that collect, stockpile, and disseminate information could stockpile information organized about each of the critical metals.

71. Mechanisms should be developed to induce the disclosure of proprietary information on properties of substitutes

for critical metals during an emergency.

GENERAL

Finding

72. The basic role of Government is to perform critical basic research that may be too costly and/or too risky

for private industry alone (long range/high risk).

Recommendations

73. Economic incentives for the displacement of some critical metals are weak. Anti trust limitations on cooperative

research should be examined to determine whether they can be waived to encourage the development of substitutes

for critical metals such as chromium.

74. Priorities which would be invoked for allocating critical metals in an emergency should be made known to all concerned industries, to encourage rational planning for emergency substitution.

75. DOC recommendations should include Government funding of special alloy development and the building of

a data base containing the resulting information for use during an emergency. Primary attention should

be given to the most critical oxidation and corrosion resistant applications. Likewise, data should

also be organized for applications where substitution and conservation are not economical under normal conditions, such as with heat teated steels.

76. The development of conservation options cannot be justified by industry solely as a hedge against possible

periodic shortages because the cost of industrial R&D, and its implementation, must be justified by the return on investment regardless of shortage considerations. Investment in such options purely as a protection

against future potential shortages is a Government responsibility.

77. The Government is providing support for critical metals conservation in aerospace materials, i.e., cobalt,

through established funding agencies. Large savings of critical metals may be possible in commercial application,

but industry may be unable to support such advanced programs. After certain processes with limited aerospace

and military application have been shown to be viable, the Government may have to act as "champion" for continuing

development and pilot utilization. Methods of providing support would have to be established.

PR1-17
TABLE V

Rating Form

This rating form is to be used in evaluating the findings and recommendations. You may agree strongly,

agree, disagree, or supply a modified statement in evaluating the findings. In evaluating the findings simply

check ( ) the preferred response. Recommendations are to be evaluated for importance, effectiveness, and ease

of implementation. In evaluating the recommendations, enter the number of your preferred response. For example, enter (4) if you regard a recommendation as being of Minor Importance. The three rating scales for the recommendations

are given below. If you disagree with a recommendation simply indicate your disagreement with a check ( ), and

if you choose to do so supply a statement. Please return this rating form in the enclosed envelope by July 10.

IMPORTANCE EFFECTIVENESS EASE OF IMPLEMENTATION

1 . Of Major Importance 1 . Very Effective 1 . Will certainly be implemented through

2. Of Moderate Importance 2. Moderately Effective private action alone.

3. Of Limited Importance 3. Possibly Effective 2. Would be implemented through private

sector actions with appropriate changes

4. Of Minor Importance 4. Probably not Effective in public policy.

5. Of No Importance 5. Would not be Effective 3. Could be implemented through private

sector action alone.

4. Is unlikely to be implemented through

private sector action without appropriate

changes in public policy.

5. Would not be implemented in the forseeable

future through private sector action even with appropriate changes in public policy.

FOR EVALUATING FINDINGS. FOR EVALUATING RECOMMENDATIONS

ITEM AGREE AGREE DISAGREE MODIFIED IMPORT- EFFECTIVE- EASE OF DISAGREE (SUPPLY NUMBER STRONGLY STATEMENT ANCE NESS IMPLEMEN- STATEMENT IF SUPPLIED TAT I ON DESIRED) CHROMIUM

1 .

4 .

5 .

6 .

7.COBALT

8 .

9. 10 .

11 . 12 . TANTALUM

13.

14.

15.

16.

17. TITANIUM

18.

19. 20 .

21 . 22 . 23.

24.

25. COMPOSITES

26. 27.

28.

29.

PR1-18
30 .

31 . 32 . 33 . 34 . 35 . RAPID SOLID- IFICATION

36 . 37 . 38 . 39 . 40 .

41 . 42 . 43 . 44 . 45 . COATINGS

46 . 47 . 48 . 49 . 50 . DOMESTIC AND

NEAR DOMESTIC MATERIALS

51 . 52 . 53 . 54 . 55 .

56 . 57 . INFORMATION FOR EMERGENCY

EMERGENCY SUBSTITUTION

58 . 59 . 60 . 61

.

62

.

63 . 64 . 65 . 66 . 67 . 68 . 69 . 70 .

71 . GENERAL

72 . 73 . 74 . 75 . 76 . 77 .
TABLE VI

NUMBER OF RESPONDENTS ASSIGNING EACH RATING TO THE FINDINGSPOSSIBLE

ITEM NUMBER

STRONGLY

AGREE

AGREE DISAGREE MODIFIED STATEMENT WAS SUPPLIED

CHROMIUM

1 . 17 57 3 1

2. 33 38 8 0

3. 32 44 5 2 COBALT

8. 40 31 2 1

9. 24 40 3 1 TANTALUM

13. 12 27 16 0

14. 4 37 3 0

15. 25 29 2 0

16. 17 34 3 0 TITANIUM

18. 17 31 4 1

19. 5 35 13 2

20. 19 33 6 0

21. 10 36 10 0

COMPOSITES

26. 23 30 4 1 27. 16 36 5 0 28. 23 32 5 0 29. 18 30 7 1 30. 13 33 5 1 31. 12 30 6 2 RAPID SOLID- IFICATION

36. 15 39 5 1 37. 11 46 0 0 38. 14 35 7 1 39. 19 36 1 0 40. 17 34 3 2 41. 7 42 5 1 42. 20 34 2 1 COATINGS

46. 26 36 2 0 47. 13 44 4 0 48. 9 26 11 2 49. 25 30 3 1 DOMESTIC AND NEAR DOMESTIC MATERIALS

51. 33 29 0 1

PR1-20
INFORMATION FOR EMERGENCY SUBSTITUTION

58. 28 33 2 0 59. 15 44 1 1

60. 18 36 3 1 61. 14 42 2 0

62. 19 42 0 0

63. 16 44 2 0

64. 5 47 8 0

65. 9 45 6 0 GENERAL

72. 41 19 15 4

PR 1 - 21
TABLE VII

NUMBER OF RESPONDENTS ASSIGNING EACH POSSIBLE RATING

TO THE CANDIDATE RECOMMENDATIONS

ITEM IMPORTANCE EFFECTIVENESS

NUMBER

1 2 3 4 5 1 2 3 4 5 CHROMIUM

4. 38 31 7 1 1 19 32 19 6 1

5. 14 25 19 9 1 9 16 29 12 3

6. 40 18 12 4 1 19 23 20 9 2

7. 39 32 7 1 1 24 39 10 3 1 COBALT

TO. 42 23 3 2 0 24 34 8 1 0

11

.

29 26 11 0 0 17 27 19 1 0 12. 16 23 18 3 1 12 20 23 3 1 TANTALUM

17. 23 22 6 0 0 10 20 13 1 1 TITANIUM

22. 22 15 10 0 0 13 15 16 2 0 23. 27 15 7 1 0 21 11 14 2 0 24. 22 18 4 1 0 14 21 7 1 0 25. 10 19 15 4 0 11 18 15 3 0 COMPOSITES

32. 22 27 8 2 0 11 23 18 4 0 33. 17 27 10 3 0 13 29 9 4 0

34. 25 20 7 3 0 22 15 13 3 0 35. 25 25 3 0 1 19 26 5 1 0 RAPID SOLID- IFICATION

43. 13 18 9 1 1 8 16 14 3 1 44. 19 19 6 1 1 14 18 12 1 2 45. 23 23 3 2 1 17 23 10 0 1 COATINGS

50. 26 22 9 2 0 20 23 13 3 0 DOMESTIC AND

NEAR DOMESTIC MATERIALS

52. 23 26 14 0 0 19 25 17 1 0 53. 27 19 4 2 1 15 23 12 2 1 54. 11 15 13 4 1 8 15 12 7 1 55. 14 26 3 1 0 13 22 6 2 0

56. 17 26 4 1 0 14 25 8 1 0 57. 23 26 4 0 0 20 23 9 1 0 INFORMATION

FOR EMERGENCY SUBSTITUTION

66. 31 20 4 1 1 23 23 8 0 1 67. 22 26 9 1 0 18 23 13 1 0 68. 34 20 4 1 0 23 26 7 0 0 69. 26 28 4 3 0 17 32 7 1 0 70. 25 29 5 1 0 22 30 6 0 0 71. 18 19 n 5 0 11 17 16 7 1

MEANS OF DISAGREE WITH IMPLEMENTATION STRUCTURE OF

1 2 3 4 5 STATEMENT

1 7 8 49 n 2

0 5 5 33 24 7

0 15 15 30 13 4

7 20 20 24 5 1

3 10 17 30 7 1

6 14 15 25 4 5

11 7 27 13 3 4

2 8 12 19 7 5

1 9 7 26 2 6

5 6 15 21 1 1

1 12 5 21 4 7

6 4 22 13 2 2

3 7 18 23 6 1

3 7 22 16 7 1

6 11 23 7 4 3

6 7 28 7 3 0

1 10 6 20 3 14

4 4 14 17 5 4

1 12 3 26 7 4

0 12 11 27 7 2

6 15 19 19 2 1

1 6 2 33 8 7 0 6 1 26 10 14

1 14 1 22 3 13

0 17 3 22 7 10

1 11 0 34 5 8

1 11 8 25 11 1

0 9 7 28 9 2

0 12 9 29 6 0

2 13 8 26 7 0 4 12 12 25 5 1

0 4 4 29 16 4

PR1-22
GENERAL

73 . 22 24 9 4 0 11 26 16 5 0 0 8 3 33 11 6

74 . 36 25 5 0 0 19 24 9 3 0 2 13 4 33 12 0

75 . 32 18 6 3 0 21 27 6 3 2 0 10 2 30 15 7

76 . 25 14 7 2 1 17 17 9 2 1 0 6 4 22 16 16

77 . 25 26 5 2 0 20 25 9 3 0 0 7 1 33 15 6

PR1-23
WRITTEN SUBMISSION TO WORKSHOP

James I. Mueller, President

American Ceramic Society

wi
ocietujI /lie.

Reply To

Ceramic Engineering Division, FB-10

University of Washington

Seattle, Washington 98195

Telephone (206) 543-2613

Dr. Allen Gray, Chairman

Department of Commerce Workshop

"Potential Role of Advanced Materials in the

Aerospace Industry"

Vanderbilt University

P. 0. Box 1553, Station B Nashville, Tennessee 37235

Dear Dr. Gray:

Having reviewed the workshop program without the benefit of the depth

of subject matter to be covered by your speakers, I would like to briefly

describe a few, non-inclusive activities of the ceramic community appropriate

to the general subject of the workshop. These would, by their nature, fall

in the category of substitution for critical materials.

COATINGS

Ceramic coatings have a long history for the protection of metal surfaces

from chemical corrosion at room and moderately elevated temperatures. The use of alumide coatings on refractory metals with low chromium contact provides a protective layer of aluminum oxide which offers effectiveness in some application similar to the chromium oxide layer. Similar results have been obtained

in the past using silicide coatings.

Thin oxide coatings on low grade steels are also under development as a measure to reduce our dependence upon stainless steels. These coatings are obtained by the hydrol ization of an orqanometall ic and the subsequent controlled

polymerization of the hydrated molecules. The application of these liquid

organometal 1 ics to any complex metal stage is fairly simple and viscosity control enables control of the coating thickness. Individual, multiple oxide or graded changes in composition are possible and the moderately low temperature

processing makes them attractive from an energy viewpoint.

The recent development of chemical vapor deposition of oxides, nitrides,

silicides and other corrosion-resistent/retardant coatings also offer a wide

spectrum of possibilities.

Wl-1
Dr. Gray

June 9, 1981

Page 2

COMPOSITES

Undoubtedly, much will be covered on the utilization of glass, carbon and

possible aluminum oxide fibers in various matrices. Improvements in the understanding and properteis of these fibers continue to be of interest to a substantial number of ceramists. Newer ceramic fibers are under development and one in particular is worthy of note. Several companies have introduced fibers

of silicon carbide which offer possibilities for use in room and elevated

temperature applications. These are available as monofilaments and as two and

three dimensional woven fabrics or as a felt. The results of laboratory

studies utilizing these fibers in aluminum, beryllium and ceramic matrices are extremely interesting and certainly worthy of further study and scale-up.

Studies of ceramic matrix composites are infantile relative to those using

polymeric and metal matrices. Work is progressing on the use of both fibrous

and particulate reinforcement with long term possibilities seen in each. An

example of the latter is the use of a phase transformation "toughener" material,

such as zirocnium oxide, in normally monolithic ceramics.

One system to receive considerable attention and some use has been the

carbon-carbon composites. Although their strength to weight ratios have been

recognized their inability to withstand oxidation at elevated temperatures

have limited the use in many areas. The recent success of a silicon carbide

coated carbon-carbon composite as the nose-cap and wing leading edge components

of the space shuttle orbiter gives some evidence of the future applicability of

this material --especial ly since improved coatings and processing are available--

including chemical vapor deposition.

MONOLITHIC CERAMICS

The past few years has seen a remarkable interest and improvement in the

so-called advanced ceramics--primarily the silicon-based materials namely

alpha silicon carbide and silicon nitride. One of the primary purposes of the

DARPA program initiated in 1971 for the development of ceramics for the gas

turbine engines wa c- the search for a substitute for strategic materials.

Considerable progress has been made in these materials with the aid of substantial funding from several federal agencies. The rate of progress in this

country over the past few years has not kept pace with those of our international

colleagues, principally from W. Germany and Japan. It is my personal belief

that the reason for this has been the lack of a coordinated program for the

improvement of materials processing and properties. These basic aspects have

received but a fraction of our support level for these programs, the remainder

being allocated to develop associated hardware which cannot be utilized until

a satisfactory engine material is commercially available, ideally from more

than a single source.

Wl-2
Dr. Gray

June 9, 1981

Page 3

A considerable effort must be made, if we are to be competitive in this area and the hour glass (with its silicon-based sand) is rapidly running down.

These ceramic materials and others do offer a meaningful potential for substitution but all involved must recognize that the development of a new engineering material--be it metallic, organic or ceramic--to its full application

takes more than a decade.

DESIGN

Structural design with brittle and composite materials was nearly dormant

since the days of building stone, brick, cast iron and the advent of reinforced

concrete. This has resulted in numerous generations of design engineers who

have worked only with ductile materials whose properties were for the most

part isotropic. The continual experience with these types of materials was believed to have resulted in a prejudicial bias among designers regarding their

possible utilization of composite and brittle materials. In 1976, both RPI

and the University of Washington, with support from NASA, established academic

and research programs to improve design methodology and understanding in the

use of composite materials and brittle (ceramic) materials, respectively , in

structural application. Each of the programs has proven successful educational

experiences for young engineers. There still remains a substantial segment of

engineering designers who must accept the design methodologies unique to each

of these classes of materials if they are to be utilized in substitution for

those critical metals which are the subject of this workshop.

Engineering design always includes iteration based upon conventional

trade-offs. The substitution of non-common materials, be they coatings, com- posites or ceramics, will require a true understanding of all materials plus

the ability and willingness to develop truly interdisci pi inary communication

with all involved. This workshop should stress the need of such an understanding.

Sincerely yours,

James I. Mueller

President

JIM/cm

cc: John B. Wachtman, Jr.

Arthur L. Friedberg

Wl-3

NBS-114A (REV. 2-80

U.S. DEPT. OF COMM.

4.

BIBLIOGRAPHIC DATA

SHEET (See i nstruction s)

1. PUBLICATION OR

REPORT NO. NBSIR 82-2495

2. Performing Organ. Report No 3. Publication Date

April 1982

TITLE AND SUBTITLE

CONSERVATION AND SUBSTITUTION TECHNOLOGY FOR CRITICAL MATERIALS--Proceedings

Public Workshop sponsored by U.S. Department of Commerce/National Bureau of

Standards and U.S. Department of Interi or/Bureau of Mines. VOLUME II.

of

5. AUTHOR(S)

Allen G. Gray

6. PERFORMING ORGANIZATION (If joint or other than N BS, see in struction s) 7. Contract/Grant No.

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

WASHINGTON, D.C. 20234

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

Department of Commerce Department of the Interior

National Bureau of Standards and Bureau of Mines

Washington, DC 20234 Washington, DC 20241

10.

SUPPLEMENTARY NOTES

P Document describes a computer program; SF-185, FlPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a sign ificant bibliography or literature survey, mention it here) The United States is highly vulnerable to problems in supply of critical and

strategic materials and it is recognized that there is a whole soectrum of options

for responding to such crises. While a number of supply oriented options are under study by various groups, the focus of this Workshop was on the technical

opti ons

The Workshop was held principally to develop information for the report

required by the Department of Commerce, but should also be useful to the other

agencies in their responsibilities. The DoC report is supposed to identify a materials needs case related to national security, economic well-being, and

industrial productivity, to assess critical materials needs, and to recommend

programs to meet these needs.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) Critical materials:, strateoic materials; conservation*- substitution;

chromium; cobalt; titanium; tantalum.

13. AVAILABILITY 14. NO. OF

PRINTED PAGES

Qy] Unlimited

[ j For Official Distribution. Do Not Release to NTIS 579

i Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 15. Price

iXJj Order From National Technical Information Service (NTIS), Springfield, VA. 22161 $40.50

USCOMM-DC 6043-P80 <MJ.S. GOVERNMENT PRINTING OFFICE: 1982-360-997/2096