IMSE

Institute for Materials Science and Engineering

NAS-NRC

Assessment Panel

January 21-22, 1988

CERAMICS

NBSIR 87-3612

U.S. Department of Commerce

National Bureau of Standards

Copper

o

Barium

O

Yttrium

Oxygen

Technical Activities

1987
The crystal structure

illustrated is that of

Ba2 YCu3 C> 7 , a superconducting

oxide with a transition

temperature of 90-95K.

Crystallographic analysis

performed at the NBS was the

first determination of the

structure of this important

compound which clearly

identified the structure as orthorhombic and specified

the lattice sites of the oxygen

atoms.
Institute for Materials Science and Engineering

CERAMICS

NAS-NRC

Assessment Panel

January 21-22, 1988

NBSIR 87-3612

U.S. Department of Commerce

National Bureau of Standards

Technical Activities

1987

TABLE OF CONTENTS

Page

INTRODUCTION v

TECHNICAL ACTIVITIES

PROCESSING

GROUP

Ceramic Powder Characterization. .... .Alan Dragoo . ............. 1 Processing Science. ................. .Edwin Fuller. ............ 5 Ceramic Chemistry and Bioprocesses ... Frederick Brinckman. . . . . . 11

.STRUCTURE/STABILITY

High Temperature Chemistry .John Hastie. 17

Synchrotron Radiation. .............. . Masao Kuriyama 21

Glass and Composites ................. Stephen Freiman. ......... 27

PROPERTIES/PERFORMANCE

Mechanical Properties ................ Sheldon Wiederhorn. ...... 31

Tribology. .Said Jahanmir. 35

Optical Materials ................... .Albert Feldman. .......... 39

Computerized Data Activities. ....... .Camden Hubbard. .......... 43

RESEARCH STAFF 49

OUTPUTS AND INTERACTIONS

Selected Recent Publications .................................. 60

Selected Technical/Professional Committee Leadership. ......... 67

Industrial and Academic Interactions .......................... 71

Standard Reference Materials

APPENDIX

Organizational Chart

Ceramics Division

Organizational Chart

National Bureau of Standards

Organizational Chart

Institute for Materials Science and Engineering

iii
-

.
INTRODUCTION

Introduction

Ceramic materials are becoming increasingly important in our technological

society in a variety of sophisticated electronic, optical, and mechanical

applications and the intense international competition in this field has

demonstrated the value of close industrial, academic and governmental

interactions. With this environment, the Ceramics Division has set as its

objective, the development of basic understanding, novel measurement

methods, standard reference materials, and standard reference data to

enable industry to achieve key properties of ceramic materials through

advanced processing.

In the past year, the Division has aggressively addressed this goal and

taken measures to strengthen its capabilities through staff expansion,

acquisition of sophisticated equipment and the construction and remodeling

of existing facilities. This was exemplified by the completion of the

Division's "Level 10 Clean Room," which will allow processing of ceramics

under rigorously controlled conditions. We have also initiated the design

and construction of a surface forces laboratory which will allow the

measurement of phenomena critical to our understanding of fracture,

sintering, and tribology.

In 1987, the Division was active in the newly emerging field of high

temperature superconductors through development of basic data required for

processing, as well as the measurement of physical properties of this

unique class of materials.

The Division staff has been productive in several fields of Ceramic

Research: 1) approximately 200 papers and reports were published; and,

2) 160 invited talks presented. The skill and expertise of the Division

were recognized by the appointment of Dr. Brian Lawn, a member of the

Mechanical Properties Group, as an NBS fellow and Dr. Edwin Fuller, leader

of the Processing Science Group, was awarded the Ross Purdy Coffin Award by

the American Ceramic Society.

Among the significant accomplishments by the Division in 1987 are:

o The phase diagram for the superconducting YBaCuO system was determined

and published.

o A diamond film deposition apparatus was constructed and successful

deposition of diamond films demonstrated.

o A theoretical model of the role of surface forces in subcritical crack

growth was developed.

o A time-resolved micro-Raman test system to analyze reactions at

tribological contacts was developed.

o The interrelationships between processing, microstructure, and

properties of superconducting YBaCuO were determined.

v
o A novel technique for measurement of sintering stress in ceramics was invented

.

o Low temperature "sintering" through the application of high pressure

was demonstrated, with the potential for enhanced toughness through

pressure induced phase transformations.

o As part of the International Energy Agency (IEA) international powder

characterization round-robin, 2000 silicon nitride reference powder

samples were prepared, certified and distributed.

o Standard Reference Material 6406, silicon powder, was certified for

calibration of x-ray line positions in x-ray powder diffraction.

o Techniques to predict the effect of filaments on crack growth

retardation in ceramic matrix components were developed.

o The first data on the fracture behavior of superconducting ceramics as

a function of sintering and annealing conditions were obtained.

o Volume 6 of Phase Diagrams for Ceramics was completed.

During the past year many national and international visitors from industry

and academia have come to the Division for information exchanges. Our ties

with domestic industry have been strengthened by these visits as well as through collaborative research efforts. Similar relationships with the

university community have also been strengthened through the Divisions

efforts to augment staff with university postdoctoral and graduate

students

.

In 1988, the Bioprocessing activity will be transferred to the Polymers

Division and the High Temperature Chemistry activity to the Metallurgy

Division to more effectively integrate the research of those groups into

the IMSE program. Concurrently, the Wear Group will be transferred from

the Metallurgy Division to Ceramics, again to facilitate research

integration.

We look forward to the increased emphasis on industrial cooperation, which

the establishment of the National Institute of Standards and Technology

will entail, and anticipate much greater participation with the private

sector on research of mutual interest.

S. M. Hsu

Chief, Ceramics Division

September 1987

vi
TECHNICAL ACTIVITIES
' Hi
PROCESSING

CERAMIC POWDER CHARACTERIZATION Alan Dragoo

The work of the Powder Characterization Group is focussed on measurements

of physical and phase characteristics of powders and on understanding the

effect of powder characteristics on processes of dispersion, consolidation

and sintering which convert powders into ceramics. Processing of ceramic

materials typically begins with a powder which is manipulated through

several processing steps and consolidated and sintered into a hard, solid

object. Characterization and control of properties of the starting powder

is recognized as essential to the production of high-quality ceramics

required in advanced technological applications, such as electronic

substrates, cutting tools and engine components.

The connection between powder characteristics and processing and

performance begins with the recognition that powders are complex physical

systems in which characteristics are often spatially distributed within

particles, between particle interior and surface, and between particles.

Powders, dispersions and ceramics are generally described by properties

that are based on these variable particulate ensembles. There is a critical need for Standard Reference Materials (SRM's) with certified

particle size distributions to be used in the calibration and

intercomparison of instruments for particle size measurements.

The Powder Characterization Group recognizes that the development of rapid,

on-line sensors for particle characteristics is an round-robin on powder

characterization, the JCPDS-International Centre for Diffraction Data, the

American Ceramic Society and visits to companies. Work of the group is

carried out primarily in two laboratories: the Fine Powder Laboratory and

the Automated X-Ray Diffraction Laboratory. Development of Scanning

Electron Microscopy/Image Analysis Laboratory for direct characterization

of particles and microstructures was begun with the initiation of the

purchase of a scanning electron microscope/image analysis (SEM/IA) system.

Representative Accomplishments

0 A numerical descriptor was developed for description of the fiber

distribution in fiber-reinforced composites.

0 Over 2000 silicon nitride reference powder samples were prepared

and certified for a international powder characterization roundrobin.

0 Standard Reference Material 640b, silicon powder, was certified as new reference material for calibration of x-ray line positions in

x-ray powder diffraction.

Powder Characterization

A. Dragoo, C. Robbins, J. Kelly, D. Minor

Research is carried out with a variety of instruments, including an x-ray

gravitational sedigraph, photon correlation (quasi-elastic light

scattering) spectrometer, Brunauer-Emmett-Teller (BET) surface area

1
apparatus, mercury intrusion porosimeter and automatic helium pycnometer.

Powders are characterized for research in ceramic processing, for

preparation of Standard Reference Materials, for studies of wear of ceramic

components and for development of new measurement methods. Preparation of

samples of five ceramic powders for an international round-robin conducted

on the auspices of the International Energy Agency has constituted a major

effort during the last year. Approximately, 1000 zirconia and 3500 silicon

nitride powder samples have been prepared to date. The assurance of

physical and chemical homogeneity between samples is critical to the success of the round-robin. A major effort in the statistical analysis of

the results of the round-robin was recently initiated.

Electron Microscopy/Image Analysis

J. Kelly, D. Minor, A. Dragoo

Direct characterization of particles can provide fundamental size and shape

data that not only serves to verify indirect measurements but provides data

which is not accessible by indirect means. For ultrafine particles

scanning electron microscopy (SEM) and transmission electron microscopy

(TEM) must be used to obtain high-resolution images. However, to achieve

measurements with standard errors of a few percent, on the order of 10,000

images must be measured. Consequently, automated image analysis (IA) is

required. Purchase of an integrated SEM and IA systems was initiated this

year. This will be an unique Institute facility.

The Powder Characterization Group has been assisting the Army Materials

Technology Laboratory in the development of quantitative image analysis

procedures for evaluation of composite materials. Initial work on graphite

fiber reinforced polymer material has led to the development of a quantitative descriptor for variation in fiber distribution. This

descriptor can be compared with computer generated simulated random

dispersions. Establishment of such a descriptor is viewed as the first

step toward the development of quantitative description of ceramic

composite microstructures. The ultimate goals of this work are: 1) to

develop Standard Reference Materials for two phase dispersions and 2) to

obtain numeric image descriptors of composites which correlate with their

mechanic properties.

An SEM study was conducted in collaboration with the Optical Materials

Group on thin diamond films formed by electron assisted chemical vapor

deposition using 99.5 percent H2 and 0.5 percent CHA at 40 Torr pressure.

High-quality micrographs showed the development of individual diamond

crystals which evidenced multiple twinning. The deposition process was followed from individual crystals to the development of a continuous film.

Application of X-ray Diffraction to Ceramic Processing

J. Cline

Research in the field of x-ray diffraction is centered around the

broadening of its application to the characterization of ceramic materials

before, during and after processing. The aim is to assist the development

of process characterization and modeling that is applicable to a broad

2
range of ceramic systems. Investigation of the application of XRD to

quantitative analysis has lead to the isolation of microabsorption and

extinction effects. With the use of a high- temperature x-ray

diffractometer these effects can be used to measure grain growth during

sintering. High- temperature studies are planned to measure grain growth

and orientation effects in thin films of superconducting oxide materials.

Standard Reference Materials For X-Ray Diffraction

C. Robbins, C. Hubbard, J. Cline, A. Dragoo, M. Kuchinski 1

, Y. Zhang2

, W. Wong-Ng2

, J. Stewart2, T. Nakamura3

, L. Domingues 4

1 Guest Scientist, Rutgers University

2 Guest Scientist, University of Maryland

3 Guest Scientist, Meiji University, Japan

4 Guest Scientist, Trans Tech, Adamstown, MD

Work on SRM's has focused on the certification of SRM 640b to replace SRM

640a, which is now depleted, and on the certification of a new quantitative

SRM for respirable cristobalite (SRM 1879) . A synthesis method for the

preparation of alkali-stabilized tridymite has been scaled up to produced

material in quantity for a respirable tridymite SRM. Several silicon

nitride powders, including a beta-silicon nitride powder, for investigation

of alpha/beta phase ratios in bulk and surface compositions. The silicon

nitride study is using both x-ray diffraction and Fourier transform

infrared spectroscopy. Research is being carried out in collaboration with

the University of Maryland to develop a method for certification of an ultrafine crystallite size standard by x-ray line broadening (XRLB)

.

During the past year a magnesium oxide material was found which shows

considerable promise as an SRM for this application.

X-Ray Diffraction Reference Patterns

W. Wong-Ng1

, H. McMurdie2, B. Paretzkin2

, C. Hubbard, A. Dragoo

1 Guest Scientist, University of Maryland

2 Guest Scientist, JCPDS, Swarthmore , PA

Expansion of the market for new ceramic materials and the increased use of

computer automation in x-ray diffraction combine to accentuate the needs

for improved reference data in the Powder Diffraction File (PDF) and for

additional data for new phases. As an integral part of a continuous effort

of NBS to develop measurement methods and data to further the manufacture

and use of ceramic materials, NBS is carrying out a program, which is

supported by the JCPDS-International Centre for Diffraction Data, to highquality x-ray diffraction patterns and data for new phases of advanced

ceramic materials. These materials include oxides of importance as electronic materials and borides, carbides, nitrides, silicides, selenides

and tellurides which are important for engine components and cutting tools

due to their high strength or hardness. A total of 65 experimental and 35

calculated patterns were produced and submitted for publication by the

JCPDS-ICDD. These patterns included high Tc superconductor and related

phases in the Ba0-Y2 03 -Cu0 system. Phases characterized included

Ba2 YCu3 07 , Ba2 YCu05 , Ba2 YCu3 06 8 , Ba2YCu3 06 , BaCu02 , Ba2 Cu03 , BaY2 Cu0 5

,

3
Ba3 Y4 Og , BaSm2 Cu05 , BaYb2 Cu0 5 , and La x 8 Sr0 2 CuO^. In conjunction with the

production of x-ray patterns a study was carried out on the phase

transition of Ba2 YCu3 Ox from the orthorhombic to tetragonal form.

AC Impedance Spectroscopy

A. Dragoo, J. Kelly, J. Sung (Student)

The application of AC impedance spectroscopy to the characterization of

slurries and of ceramics during processing was initiated this year.

Aqueous slurries of zirconia powder were investigated over a concentration

range of 0.08 to 0.4 volume percent powder. Using gain-phase measurements

a significant decrease in gain was observed at a concentration of about

0.25 percent. Interpretation of this response is in progress.

In collaboration with the Processing Science Group, zirconia compacts were prepared and sintered at various temperatures and firing times. Samples

are being characterized by measurements of grain size and by measurement of

the complex AC impedance.

4
PROCESSING SCIENCE Edwin R. Fuller, Jr.

The program of the Processing Science Group has as its broad objective the

development of a science and technology base for ceramic processing, relating processing both to ceramic microstructures, which are developed, and to

material properties and performance, which these microstructures determine.

The research effort is in three principal areas: (1) sintering science,

(2) microstructural properties, and (3) processing-property relations. In

the first area, critical factors influencing ceramic sintering, such as,

chemical composition and stress, are addressed. In the second area, microstructural and interfacial properties, such as interatomic forces, surface

and grain-boundary energies, and defect and impurity concentrations and

their formation energies are studied and related to ceramic sintering. In

the third area, relations are studied between these microstructural features and resulting properties, such as, toughening behavior for structural

ceramics and superconducting behavior for high-Tc ceramic superconductors.

Representative Accomplishments

o Enhanced cognizance of the importance of chemical composition on sintering of advanced ceramics has resulted in the design and construction of an ultra-clean ceramic processing facility for controlling

chemical composition and determining its influences on sintering.

o Demonstration of low- temperature "sintering" of advanced ceramics

through the application of high pressure, with the potential for

enhanced toughness by pressure- induced phase transformations.

o Development of a novel measurement technique for characterizing the

"differential sintering stresses" that develop during the sintering of

ceramics with second-phase heterogeneities and/or reinforcing fibers.

o First confirmed observation of diffusion induced grain-boundary

migration in an oxide ceramic, MgO by diffusion of NiO solute.

o Theoretical formulation using a lattice statics Green's function

method for calculating the atomistic structure and energy of grainboundary interfaces in ionic ceramics.

o A novel fracture mechanics specimen for evaluating the interaction of

matrix cracks with reinforcing fibers in ceramic matrix composites,

and thereby the interfacial properties developed during processing.

o Elucidation of the interrelations between processing, microstructure,

and superconducting properties for new high Tc ceramic superconductors

of the type YBa2 Cu3 07

_ x , including the influence of annealing conditions and sintered density on the superconducting transition, and the

influence of milling media on superconducting phase composition.

5
SINTERING SCIENCE

J.E. Blendell, S. Block, T.W. Coyle, U.V. Deshmukh1

, E.R. Fuller, Jr.,

C.A. Handwerker2

, C.P. Ostertag3

, G.J. Piermarini, L.C. Stearns, M.D.

Vaudin* , C.A. Harding, and C.A. Shen

1 Guest Scientist, Drexel University

Metallurgy Division, IMSE

3 Guest Scientist, University of California, Santa Barbara

4 Guest Scientist, Cornell University

Chemical Composition : Impurities are known to dominate sintering and

microstructure development in ceramics. Quantitative understanding,

however, is lacking for the mechanisms, by which impurities and chemical

composition, in general, affect sintering. To facilitate studies of these

phenomena, an ultra-clean ceramic processing facility with an extrapolated

cleanliness of Class 10 has been designed and constructed during the past

year. This laboratory permits the production of ceramic powders with

controlled impurity levels, thereby permitting the influence of chemical

composition on sintering to be elucidated. Impurity concentrations in the

powders will be measured and contamination introduced during various

processing steps (i.e., synthesis, compaction, calcination and sintering)

documented

Pressure Sintering : Ceramics are usually sintered at high temperatures,

occasionally with the assistance of moderate pressures. An interesting

alternative for producing ceramics with potentially superior properties is

"high-pressure sintering" at low temperature. Such a process can be

accomplished by high-pressure compaction of the material, thereby reducing

voids, breaking down aggregates, and enhancing interparticle contact,

followed by low- temperature "sintering" under high pressure. Processing by

this concept of pressure sintering has been applied to ZnS , the toughening

of which is of interest for infrared windows, and to YBa2 Cu3 07 ceramic

superconductors. Preliminary results on ZnS in a diamond anvil cell are very encouraging. Processing pressures, initially at 8.4 GPa, have

progressively been lowered to a combination of cold pressing at 2.2 GPa

followed by sintering at only 550 MPa and 500°C for 5 hours.

Microindentation tests give a hardness of 3.4 ± .1 GPa and a toughness, Kc

of 1 55 ± .15 MPa.mH, which is greatly superior to values obtained for both

hot-pressed (Kc=0.44) and CVD (Kc=1.0) prepared ZnS. For YBa2 Cu3 07 superconductors, cold pressing at 4.5 GPa followed by sintering at 1.6 GPa

and 500°C for 1 hour gives a hardness of 5.5 ± 1.5 GPa. As no cracks were

observed, toughness could not be determined. X-ray diffraction

measurements of atomic cell volume versus pressure give a bulk modulus of

196 ± 17 GPa. Extension of pressure sintering to larger samples is being

explored with large presses.

Sintering Ceramic Composites : Fiber reinforced ceramics are generally

produced by hot-pressing, in order to achieve full density and thereby good

properties. The inability to sinter such materials in the absence of

pressure derives from the presence of already dense fibers. These fibers cause stresses to develop during sintering, due to the constraints they

impose on the contracting matrix. A new method has been developed to

reveal, monitor, and measure these stresses during densification of ceramic

6
composites, by incorporating a layer of SiC fibers between two layers of

ceramic powder of different thicknesses. Upon sintering, this

configuration produces an asymmetric stress field across the thickness of

the specimen, which results in bending of the compact, as characterized by

curvature of the fibers. To relieve this stress development, polymer

coating of an appropriate thickness have been applied to the fibers. The

polymer burns off at the relatively low temperature of 600°C, producing a gap between the matrix and fibers, thereby allowing the matrix to shrink in an unconstrained manner onto the fibers. During sintering no stresses were observed and after sintering the composite reached the same final density

as the monolithic material.

MICROSTRUCTURAL PROPERTIES

J.E. Blendell, E.R. Fuller, Jr., C.A. Handwerker, R.F. Krause, Jr.,

L.C. Stearns, V.K. Tewary1

, M.D. Vaudin, C.A. Harding, and C.A. Shen2

1 Guest Scientist, Ohio State University

2 Summer Student, Massachusetts Institute of Technology

Interfacial Stability in Ceramics : Of particular importance to the

properties and performance of advanced ceramic materials, during both

processing steps and in-service use, is the stability of boundaries and

interfaces in these materials. Diffusion induced grain-boundary migration

(DIGM) is a mechanism, by which otherwise stable boundaries can be induced

to migrate, due to the diffusion of a solute into or out of the material.

In the past year DIGM has been studied in the MgO/NiO system. Sintered MgO

specimens were exposed to NiO at 1100 C to 1300 C for times up to 100

hours, and their microstructures characterized by optical and electron

microscopy. Similarities with DIGM in metallic systems were found, with

boundaries migrating up to 5 /im. Alloying of the regions in the vicinity

of the grain boundaries was observed, together with an increased

dislocation density and a change in lattice parameter caused by the change

in chemical composition.

IEA Ceramic Characterization : The reproducibility and precision, with

which ceramic microstructural properties can be measured, has not been as- sessed in a systematic manner for advanced ceramic materials. The objective of this work is to measure and characterize ceramic properties (crystalline phase composition, grain-boundary properties and possible surface

residual stresses) for a series of standard ceramic specimens to assist in

the development of internationally accepted standards for ceramics

characterization. The work will contribute to an international roundrobin, IEA ANNEX II, Subtask 3 on Ceramics Characterization, under the

auspices of the International Energy Agency. To date an ESK silicon

carbide material has been examined by transmission electron microscopy.

Observations show that the material is mainly a-SiC of the 6H polytype with

a 1-3 ^m grain size. The microstructure is essentially equiaxed, with a number of grain boundaries lying in the basal plane of one of the adjoining

crystals. The grain boundaries are not decorated by any precipitates at a resolution of 2 nm.

7
Structure and Energy of Ceramic Grain Boundaries : Theoretical studies have

been undertaken to elucidate the structure and energy of ceramic grain

boundaries, and their dependence on defect and chemical composition. A

Green's function method has been developed for these calculations. Using a coincidence-site-lattice as a reference state, the Green's function is

obtained in terms of the perfect lattice Green's function by mapping

lattice sites of the reference state to the perfect lattice, and then

solving the appropriate Dyson's equation. This Green's function gives the

response of the reference state to the non-equilibrium forces, thereby

determining the atomistic structural relaxations. Both harmonic and

anharmonic theories have been developed. For purposes of illustration, the

method has been applied to a £5 tilt boundary in both copper and a simplistic model of MgO . The method is being extended to include

dielectric effects to model better grain boundaries in ionically-bonded

ceramics

.

PROCESSING- PROPERTY RELATIONS

J.E. Blendell, S. Block, T.W. Coyle, U.V. Deshmukh, E.R. Fuller, Jr.,

R.F. Krause, Jr., C.P. Ostertag, T.R. Palamides 1

, G.J. Piermarini,

L.C. Stearns, M.D. Vaudin, C.A. Harding, and C.A. Shen2

1 Guest Scientist, Drexel University

2 Summer Student, Massachusetts Institute of Technology

Ceramic Matrix Composites : Low and high- temperature mechanical performance

and structural stability of ceramic matrix composites is controlled to a large extent by the structure, properties and stability of fiber-matrix

interfaces. Techniques to characterize these interfacial properties and to

relate them to both processing and macro-scale mechanical behavior are required to develop reliable ceramic composites. Experimental studies have

been undertaken to develop the understanding necessary to bridge the gaps

between processing, the nature of the fiber-matrix interface, and the

performance of bulk composite materials. Three scales of behavior are examined: micro-mechanical behavior of individual fiber-matrix interfaces

is characterized by an instrumented indentation technique; interactions of

matrix cracks with simple arrays of fibers are investigated by a novel

fracture-mechanics specimen with controlled fracture behavior; and the

performance of bulk composites (uniaxial and woven- fiber reinforced

materials and whisker- toughened materials) is examined for various failure

modes. Although composites from external sources have been examined, much

of the effort has centered on the development of a model composite system,

composed of a borosilicate glass matrix containing SiC monofilament fibers.

Specimens, designed for examination of the three scales of behavior, have

been fabricated from these components using nearly identical processing

conditions. These coordinated studies, conducted in collaboration with the

Glass and Composites Group, permit the relations between processing and

mechanical behavior at the three scales to be directly correlated.

Ceramic Superconductors : The interrelations between processing,

microstructures, and properties is particularly important for the new high

Tc ceramic superconductors. To elucidate these interrelations, YBa2 Cu3 07

. x superconducting ceramics (with x in the nominal range of 0 to 1) have been

8
fabricated, their properties measured and related to microstructure and

processing conditions. Materials were prepared by powder processing

techniques, followed by dry pressing and sintering in both air and flowing

oxygen at various temperatures. Sintered bodies were annealed at various

temperatures and environments to enhance superconducting properties, such

as, transition temperature and transition width. These properties, as measured by electrical conductivity and AC magnetic susceptibility, as well

as microstructure showed strong sensitivity to processing conditions:

annealing atmosphere, temperature, and sintered density. Compositional

mapping proved to be an important method for quantifying microstructure

variations

.

A major impediment to the use of high Tc superconducting ceramics is their

brittleness, with a fracture toughness of only ~1 . 2 MPa.mh. To enhance

sintering, and hence structural properties, powder is milled to small

particle sizes. During this process, the orthorhombic superconducting

phase of YBa2 Cu3 07

_ x underwent low- temperature chemical reactions with

various milling media. The chemically modified powder has a tetragonal

structure and is non- superconducting. The orthorhombic structure, and

hence superconductivity, can only be fully regenerated by annealing at

950°C. In addition, these modified powders are extremely reactive with

reinforcing fibers or whiskers, added to enhance the fracture toughness and

strength

.

High-Pressure Transformation Toughening : Transformation toughening is a well-known and effective method for enhancing the fracture toughness of

ceramic materials. Transformation toughening by the retention of highpressure metastable phases is a concept that originated at NBS . Criteria

necessary for such toughening require the toughening agent to exist

metastably at ambient pressures and temperatures and to have a rapid,

reversible, pressure- induced, phase transformation. This new approach to

toughening is currently being applied on a U.S. Navy program to develop

tougher, infrared- transmitting missile windows. Such windows must consist

of tough, relatively transparent nonoxide materials, such as chalcogenides

or phosphides. Candidate samples from a number of sources have been

studied in the diamond anvil cell. Six potential toughening agents, Til,

TiGaSe2 , TiInS2 , Gd^Sey, SrNd2 S 4 and Ag3 SbS 3 , have been identified, the

first three of which possess rapid, reversible transitions at low pressures

(less than 500 MPa). Preliminary measurements on toughening ZnS with Til

show a 30% toughness increase over hot-pressed materials.

Transformation Toughening in Zr02

: Enhanced use of tetragonal Zr02 as a toughening agent requires a thorough understanding of the transformation

thermodynamics and kinetics, especially the relative influence of

mechanical versus chemical driving forces. In the past year, in

collaboration with R. Ingel of the Naval Research Laboratory, temperature

dependence of the fracture toughness, strength, and yield stress has been

measured for an unstabilized, skull-melt grown crystals of Zr02 from room temperature to 1500°C. Results indicate a clear transition from yield

controlled by dislocation slip at high temperatures to yield controlled by

stress - induced transformation below 1200°C. Fracture toughness results

indicate that a toughening mechanism is operative at temperatures, where

the tetragonal phase is thermodynamically stable in the absence of a constraining stress.

9
Decomposition Kinetics of Energetic Materials : A Fourier transform

infrared (FTIR) microspectroscopic method is used in conjunction with a diamond anvil cell to obtain pressure- temperature data for thermal

decomposition kinetics of energetic materials, such as, RDX, HMX, TNT, and

nitromethane . Current work involves the study of ni trome thane , its

reactivity and phase diagram. Although no new phases were found, under

some conditions, single crystals at room temperature spontaneously explode

with the application of nonhydrostatic stress. A deuterated analogue, on

the other hand, did not explode. The decomposition reaction rate increased

rapidly with both temperature and pressure, indicating a bimolecular- type

reaction mechanism.

10
Ceramics Chemistry and Bioprocesses Group Frederick Brinckman

In the past year the Ceramic Chemistry Group was joined with the Surface

Chemistry and Bioprocesses Group. These Groups had both emphasized

molecular level approaches to materials processing and performance. This

joining has thus strengthened and centralized the respective expertise and

facilities for molecular- level characterization, understanding and

monitoring of chemical and biological processes important to inorganic,

especially ceramic materials.

The Group conducts research in (1) the application of modern chemical

approaches to improved processing of ceramics and (2) in chemical and

microbiological processes important in materials processing, performance

and durability. The objectives of the Ceramics Chemistry and Bioprocesses

Group are to provide data, measurement methods, concepts and standard

materials related to chemical aspects of ceramics processing, chemical and

microbiological processing of ores, wastes and fossil fuels and performance

of inorganic materials in service environments.

Representative Accomplishments

o Two different low temperature chemical precipitation routes to the

high Tc Y-Ba-Cu-0 superconductor material have been developed. After

firing pellets of these materials at ~900°C and annealing in 02 at

600°C, sharp transitions in resistivity and magnetic susceptibility

were measured at ~86k. These procedures represent an initial advance

towards controlled synthesis of superconductive materials which are amenable to continuous intelligent processing.

o A convenient hermetically- sealed , inert atmosphere cell for x-ray

powder diffraction was designed and developed. The unit is a "plugin" device and requires no modification of existing service

diffractometers for use. The cell provides protection for

atmospherically sensitive materials, particularly the barium oxides

and hydroxides used in superconductor preparations. Application for a U.S. Patent has been filed.

o Quantitative infrared profiles of Si 3 NA preceramic powders were completed by generating working curves relating absorbance to

concentration for a, (3 , amorphous materials. We now can analyze the

morphological composition of Si 3 NA via a single FTIR measurement: a technique of potential value for on-line ceramic process control.

o Demonstrated that 400°C pyrolysis of easily synthesized, ambiently

stable polypyrazolyl- and polyimidazolylborates leads to amorphous

boron nitride. Pyrolysis of lanthanide complexes containing the polyBN ligands yields luminescent boron nitride precursor materials.

o Synthesized a new class of Si-N functionalized molecules that exhibit

a rich coordination chemistry with metals in both low and high

oxidation states. The coordination compounds are potential precursors

11
to silicon nitrides with unusual physical, optical, catalytic

properties

.

o Microbiological processing for metal recovery and ore beneficiation

was demonstrated using industrially-supplied ores and wastes. Cobalt

and nickel were leached from low grade ores and smelter wastes and

insoluble phosphate minerals were removed from iron ore using specific

microbiological reactions. Bioprocesses have the potential treatment

and metal recovery from ores and wastes which are currently not

economically recoverable using conventional technologies.

o Novel reactions of precious metal ions in aqueous solution with

volatile biogenic metabolites were demonstrated. The metals were reduced to elemental powders in these reactions which have potential

application in industrial metal recovery and separations, metal film

deposition and powder production.

Ceramic Chemistry

J. J. Ritter, T. D. Coyle, R. A. Faltynek, T. K. Trout 1

1 Graduate Co-op Student, University of Maryland

Within the past year, we have developed several chemical precipitation

routes to the high Tc , Y-Ba-Cu-0 superconductive materials. Satisfactory

powders of this material can be obtained by co-precipitating the metals as mixed-carbonates and hydroxides. An alternative route is derived from a heterogeneous interaction between the soluble barium and yttrium alkoxides

and an insoluble copper alkoxide. The superconductive behavior of powders

obtained by these procedures is summarized in figures 1 and 2.

Satisfactory materials are also produced by precipitation of the metals as either complex citrates or oxalates from organic solvent systems. These

different chemical systems are being evaluated as to their amenability to

continuous powder production techniques and as to their adaptability to

"intelligent processing" controls. The progress of our research in this area has been facilitated by our development of a convenient inert

atmosphere x-ray diffraction cell since the calcined, precipitated Y-Ba-CuO

powders tend to be moisture sensitive.

Synthetic studies have shown that families of compounds containing boronnitrogen or silicon-nitrogen bonds are accessible from stable starting

materials and that 400°C pyrolysis of these materials yields organic-free

precursors to boron nitride and silicon nitride. Significantly, the

compounds form coordination complexes with transition metal and rare earth

ions, thus providing potential sources for ceramic powders containing

optically or catalytically active sites locked into regular geometries as a consequence of the initial bonds in the coordination complexes prior to

pyrolysis. For example, an amorphous boron nitride material pyrolytically

synthesized from mixtures of a neutral B-N ligand and its coordination

complex with terbium(III) retains the luminescence inherent in the

coordination complex itself, supporting the above hypothesis.

12
Detailed Fourier Transform Infrared (FTIR) analysis of pure amorphous, a, and /3-phase silicon nitride has yielded working curves relating absorbance

to weight percent composition of the materials in an inert KBr matrix.

Accordingly, it is now possible to determine the morphological profile of

any mixture of the three phases of Si 3 NA from one FTIR measurement. Since

infrared analysis is faster and more convenient than traditional x-ray

powder diffraction analysis, the FTIR technique offers the promise of

rapid, on-line determination of phase conversions during Si 3 NA processing.

Chemical processes and changes in molecular structure in "sol-gel"

processing of silica by hydrolysis of TMOS were studied by a combination of

small-angle x-ray and small-angle-neutron scattering with chromatographic

techniques. Studies with specially-synthesized deuterated reagents

revealed a significant but hitherto unreported isotope effect- -a marked

inhibition of the initial hydrolysis reactions in acidic and neutral, but

not basic solutions. This observation provides potential insights into the

mechanisms of chemically-based ceramic synthesis procedures that can be

utilized for better process control and optimization. [The x-ray

scattering studies were carried out in cooperation with the Oak Ridge

National Laboratory.]

Microbiological Processing of Materials

G. J. Olson, F. E. Brinckman, K. L. Jewett, W. R. Blair, E. J. Parks,

T. Trout1

, R. Blakemore2, J. S. Thayer3

, R. M. Kelly4, W. Su4, W. P. Iverson5

, C. Sakai6

, J. Zelibor6

, D. Darnall 7, H. E. Guard8

'Graduate Co-op Student, University of Maryland

2 Guest Scientist, University of New Hampshire

3 Guest Scientist, University of Cincinnati

4 Guest Scientist, The Johns Hopkins University

5 Guest Scientist, Retired

6 Guest Scientist, University of Maryland

7 Guest Scientist, New Mexico State University

8 Guest Scientist, Office of Naval Research

The Group's activities in this area provide critical data, standards and

molecular measurement methods supporting the development of industrial

processes using microbial transformation of inorganic materials. These

activities are supported by the Office of Naval Research (bioprocessing of

strategic elements) , the Electric Power Research Institute (bioprocessing

of coal), the Office of Standard Reference Materials, and the NBS Steel

Research program.

In the past year we have demonstrated microbiological processing for the

selective dissolution of cobalt and nickel from low-grade domestic ores (Duluth gabbro) and smelter wastes (with St. Joe Minerals Corp . ) Such work

has attracted the interest of the Idaho Mining Association. Following

joint visits, we have begun consultations with members of that group and

the Idaho National Engineering Laboratory to develop novel biological and

chemical processes for precious metal recovery. Planning is underway for a major collaborative research activity to begin in the coming year. We are

13
also formally consulting with the U.S. Air Force in the development of new gallium biorecovery processes.

We have also evaluated different iron sulfide ores as suitable substrates

for the production of a metal ore bioleaching standard and have generated

data on reproducibility and processing variables associated with ore bioprocessing (Fig. 3). The international scientific and industrial

community involved in developing bioleaching processes for ore bioprocessing has made repeated requests to us for standards in this area. Concurrently, we are writing standard procedures for conducting ore leaching tests within the Metal Ore Bioleaching task group (G. J. Olson,

Chairman) of ASTM E-48 (Biotechnology) . These procedures will form the

basis for a planned international inter-comparison on determination of ore bioprocessing rates.

Under the steel research program we are investigating the upgrading of the

major raw materials of steel making: the removal of phosphorus from iron

ore and selective dissolution of copper and other deleterious metals from

steel scrap. We have found that exocellular microbial metabolites play key

roles in both of these processes. In the case of iron ore we have found

that one or more exocellular metabolites from a fungus isolated from

Chesapeake Bay dissolves insoluble phosphate minerals. We are currently

determining the identity of the metabolite using liquid chromatography

techniques. Our results have greatly encouraged Cleveland Cliffs Iron Co.

in Michigan. They have huge iron ore reserves but are mining at only half

capacity because these ores contain a relatively high concentration of

phosphorus mineral which is not economically removable using current

technology

.

We are also identifying biogenic metabolites as agents for dissolution of

copper and other impurities from steel scrap. We are investigating basic

mechanisms and relative rates of aqueous dissolution of iron and copper

from their metallic forms using iodomethane and other biogenic metabolites.

Also under the Steel and Strategic Metals projects we are investigating

prospects for direct aqueous reduction of metal ions to elemental powders

through organometallic reactions. We showed that Pt, Pd and Au ions are reduced to their respective elemental states using aqueous and gas phase

reactions with iodomethane and trimethyltin ion. Microbiologically

generated gaseous metabolites were also shown to reduce plantinum ions to

elemental platinum.

Microbes also affect the performance of materials in service environments.

In this area we are evaluating for the U.S. Navy, the effect of

microbiological films on the release of tributyltin (TBT) species from

surfaces coated with TBT-based antifouling coatings with low release rates.

Our work will identify the extent to which microbial films act as capacitors for the release of this biocide. This will influence the design

and implementation of new antifouling coatings since paints with

exceedingly low TBT release rates may be effective in preventing "hard"

fouling of ships if the microbial film contains sufficient TBT to repel

fouling larvae. Our non-destructive surface analysis capabilities of

microscopic Fourier transform infrared spectroscopy and epif luorescence

microscopy coupled with fluorescent tin ligands are assisting in imaging

and quantitating tin in the biofilm.

14
Also related to TBT research, we are conducting for the U.S. Navy a new

international measurement methods intercomparison for speciation of

butyltin compounds. More than 130 laboratories in 21 countries have been

invited to participate in the methods intercomparison.

15
RESISTIVITY

0 Pyrite leaching by T. ferrooxidans

2 -

1

0

I

GO 80 100 120 140 TEMPERATURE CK)

Figure 1. Resistivity vs. absolute temperature plots for chemically derived superconductor materials.

A. mixed carbonate/hydroxide route; B. metal

alkoxide route. Measurement performed by

C. K. Chiang.

South Carolina pyrite mean of triplicate flasks ± s.d

Figure 2. Rates of biol eaching of iron pyrite

by three strains of the ore leaching bacterium Thiobacillus ferrooxidans

(BA-4, SW9K1, ATCC 13661). Data on bioleaching measurement reproducibility

is needed for standards development and

for interlaboratory measurement

comparisons

.

Temoe r* n t u r c , K

Figure 3. AC susceptibility vs. absolute temperature plots

for chemically derived superconductor materials.

A. mixed carbonate/hydroxide route; B. metal alkoxide route. Measurement performed by C. K. Chiang.

16
STRUCTURE/STABILITY

High Temperature Chemistry John Has tie

Our research program in high temperature chemistry emphasizes the

thermodynamic, chemical -kinetic , interfacial microstructure, and molecularlevel behavior of inorganic materials in high temperature process and

service environments. Specific current objectives are (1) to provide

technical support to the Division's Ceramic Phase Diagram Data Program

through critical evaluation and modeling of phase diagrams and the

development of computer graphics for computer storage and manipulation of

phase diagrams; (2) to support the U.S. Steel Industry through development

of a thermodynamic database and solution model for prediction of slag,

refractory, and inorganic steel inclusion thermochemistry; (3) to develop

and apply (eg., to refractory ceramics and composites) a new molecularspecific methodology for obtaining thermal and chemical stability data at

ultra-high temperatures (2000 - 5000 C) for design of hypersonic transport

vehicles and various defense applications; recent surveys by NMAB and

Industry have indicated a critical need for thermochemical and other

materials property data at these temperatures; and (4) to obtain phase

equilibria, kinetic, and mechanistic data for the development of stored

chemical energy propulsion systems.

Representative Accomplishments:

• A prototype computer database and model has been developed for the

oxide systems commonly present in steel making. The model has been

disseminated to Inland Steel and several other industries for

testing and application to process design. The generic basis of

the model makes it applicable to both the blast furnace and

refining phases of steel making.

• The laser- induced vaporization mass spectrometric technique has

been further developed to include time and spatially resolved

analysis of refractory vaporization. Local thermodynamic

equilibrium conditions have been demonstrated using graphite and

boron nitride materials at temperatures of 2700 - 3900 C; hence the

method should be applicable as a new thermochemical tool under

conditions not attainable by conventional methods.

• Using the technique of transpiration mass spectrometry (developed

by NBS)

,

the key reactions between C103 F and Al were identified.

These reactions form the basis for new stored chemical propulsion

devices under development by U.S. Industry.

17
Phase Diagram Graphics. Evaluation, and Modeling

P. K. Schenck, L. P. Cook, P. Davidson1 and J. W, Hastie

1 NRC Post Doc

New computer graphics software has been developed to handle complex binary

and ternary diagrams using stand alone desk top computers. The

publication-ready diagrams for the recently completed Vol 6 of "Phase

Diagrams for Ceramists" were generated with this system. Software was also

developed to provide PC-access to the ceramic phase diagram graphics data

bank. PC-users will have the ability to retrieve data from the screen display and in a choice of user units (eg. °C, F, K, mole%, wt%) . Mixture

compositions can also be determined interactively by use of the lever rule

and the results displayed on the PC-monitor screen.

Dr. L. Cook, in collaboration with an international panel of phase

equilibria experts, has critically evaluated phase diagrams for molten salt

systems. These diagrams will form the basis of Vol. 7 of "Phase Diagrams

for Ceramists" which is expected to be completed in 1988.

Thermodynamic solution models, based on a generalized point approximation

for the principal ternary solution phases in the system CaO , MgO , FeO,

Si02 , have been combined and optimized with respect to new thermochemical

data on phase equilibria, solution enthalpies and long-range order. A

model for pyroxene crystallization from silicate liquids treats new experimental data with several simple melt-models to predict

crystallization temperatures and compositions that are within measured

experimental and analytical errors.

Steel Slae - Refractory Thermochemistry

J. W. Hastie, D. W. Bonnell, E. R. Plante, and W.S. Horton1

1 Contractor

Recent work has concentrated on developing a thermodynamic database for FeM-0 phases (M = Al , Ca, K, Na, and/or Si) necessary to model complex steel

slags. Thermochemical data are also under development for minority species

such as iron sulfides, CaF2 , sulfates, and the oxides of chromium and

titanium. The data- base for the previously developed NBS solution model now contains over 100 species (i.e. solid and liquid complex oxide

components) for over 10 atomic constituents. A new technique is being

developed, using silica self-associates , to model the positive deviations

from ideal mixing which can occur in high silica-content phases.

New experimental thermochemical data have been obtained using Knudsen

effusion mass spectrometry, for an Inland Steel Co. furnace slag specimen,

in addition to synthetic slag samples. Data obtained on potassium partial

pressures is a particularly sensitive measure of the oxide activities, as potassia forms a broad succession of strong complex interactions with all

the slag oxides. The experimental thermodynamic activities obtained are being compared with the model predictions.

18
Laser- Induced Vaporization Mass Spectrometry

D. W. Bonnell, P. K. Schenck, and J. W. Hastie

The coupling of laser heating with mass spectrometric analysis has the

potential for providing quantitative thermochemical data for refractory

materials at temperature and pressure extremes heretofore inaccessible to

equilibrium techniques. In addition, degradation of materials by high

powered lasers is important in, for example, the design of laser fusion

processes, laser welding, laser processing of ceramics (most recently,

superconducting and diamond films) , laser etching of semiconductor

components, laser annealing of surface alloys, and in the durability of

refractories in defense and space applications.

We have shown that a Nd/YAG laser system focused to power densities in the

region of 10 8 W/cm2

, is a convenient energy source for producing controlled

vapor plumes with generally negligible post-vaporization perturbation of

the neutral species identities and concentrations. The NBS LIVMS technique

utilizes time-resolved mass analysis to provide time-of-flight species

specific information on temperature, neutral precursors, and time history

of the laser heating process. The technique has been demonstrated on the

BN system at temperatures around 2700 C and the graphite system at

temperatures around 3900 C, and at total pressures in the vicinity of an atmosphere

.

Stored Chemical Energy Systems

L. P. Cook, E. R. Plante, and D. W. Bonnell

A number of fuel/oxidant reactions are of current interest to DOD and

Industry, including several which are multistage: Li/H2 0, Na2 0/H2 0, H2 /o2 ; MgAl/H2 0 , H2 /02 ; LiAl/C103 F; LiAlMg/Cl03 F; LiBe/C103 F; Li/C103 F; LiB/NF3

. Thermodynamic prediction of the products of three of these reactions has

been corroborated by equilibration of postulated products at high

temperature. Mass spectrometric observations on the thermal decomposition

of C103 F have shown that 02 , Cl2 and F2 are the likely key reactants.

Future work is planned which will determine rate constants and temperature

dependencies for the kinetics of the oxidation of individual alloy

components by Cl2 , 02 and F2

. Phase equilibrium determinations will focus

on the system Li-Al-Mg-O-F, with special regard to the entry of fluorine

into oxide phases

.

Thermogravimetric rate data, obtained on the oxidation of molten aluminum

droplets by C103 F, indicate multiple mechanisms, possibly including the

following steps: (1) nucleation and growth of A1F3 precipitation sites;

(2) edge growth of AlF3 islands followed by coalescence of islands; (3)

diffusion limited thickening of the A1F3 layer. Observations on the early

stages of the Al/C103 F reaction have also been made using high pressure

sampling transpiration mass spectrometry.

19
.

'

.
SYNCHROTRON RADIATION Masao Kuriyama

Important new materials in industry are produced by far more sophisticated

processing methods than previously utilized. These materials are to be made

with control of the buildup of layers designed at the atomic level. Success

with such materials will require the knowledge of new ways to arrange the

atoms in order to achieve the desired results. But such know- ledge, while

important and necessary, is insufficient by itself. The structure of all

materials when formed is non uniform locally often over regions of the order

of a micrometer. Therefore, as important as, or possibly even more important

than, novel materials design will be infor-mation on, and control of, these

local variations in actual materials produced by atomistic design. The

objective of the Synchrotron Radiation Group is to apply and improve the

recent advances of synchrotron radiation diffraction imaging techniques to

various advanced materials in order to develop the fundamental understanding

of the effects of defects and hetero-geneity on device performance and product

yields. This fundamental know- ledge will directly assist U.S. industrial

scientists and engineers to make high quality advanced microcircuits and

ceramics superconductors compet-itive in the world market. In this support

for intelligent processing, the group's current mission emphasizes effort

improving generic measurement methods and providing basic data that will lead

to the production of ad-vanced materials with superior properties for devices

of higher quality and improved reliability.

Representative Accomplishments

o Successful establishment of research collaboration with a consortium and

industry in the application of synchrotron radiation to opto - electronic

materials characterization.

o Successful Application of Advanced Microradiography with X-Ray Image

Magnification to Dental Research (Sub-micron resolution has been reached

even with thick samples.)

o Reconstruction of the history of layering of atoms during crystal growth

from synchrotron radiation data.

o Development of a new oscillation topographic imaging technique for

materials with unknown orientation and multigrained materials,

o Development of state analysis (momentum resolved in the in-coming and

outgoing x-rays) for the quantitative determinations of strain fields and

misorientations as separate physical quantities.

o Initiation of spatial chemical mapping of materials using fluorescence x- rays with 5 nm resolution.

o Establishment of an exclusive EXAFS beam line at the NBS/IMSE synchrotron beam line at NSLS in collaboration with CEEE.

21
Diffraction Imaging for Process Control in Commercial Crystal Growth

M. Kuriyaraa, B. Steiner, R. C. Dobbyn, U. Laor1 and H. E. Burdette

1 Guest Scientist, Nuclear Research Institute, Israel

The uniqueness of the NBS/IMSE Synchrotron Radiation Beamline, X-23A at

National Synchrotron Light Source (NSLS), Brookhaven, is based on unconventional parallel monochromatic beam optics combined with the

distinctive advantage of the small source size of the NSLS storage ring.

Diffraction imaging with this unique facility is leading to an understanding of various defects and strain fields and of their generation and

interactions during crystal growth and subsequent device manufacturing.

This capability now has attracted attention from industry in semiconductors

and optoelectronic materials, such as EG&G , Grumman, Morgan Semiconductor,

Rockwell and Westinghouse as well as from government laboratories, such as NASA and Night Vision Laboratory. The Synchrotron Radiation Group has

become a member of a consortium, the Center for the Development of

Commercial Crystal Growth at Clarkson University, working with members from

industry. The group has also developed independent collaborations with

individual industrial laboratories to establish research programs for

advanced materials for the future. Several small business crystal growers,

such as II-VI Incorporated and San Diego Semiconductor Inc, have also

requested NBS assistance and collaboration for evaluation of growth

processes. Westinghouse Research Laboratory has also proposed

collaboration with the Synchrotron Radiation Group for advanced materials

using nonlinear optics.

In this area, significant technical results include:

a) Undoped GaAs- -cellular arrays of interacting dislocations (Figure 1),

linear subgrain boundaries and their termination (the latter suggests

precursor cleavages which have not been observed before)

.

b) Doped GaAs- -four distinct regions of differing microstructure; complex

faceted growth (Figure 2), circular striations, turbulent interactions

between the two regions and linear arrays of dislocations close to the

edge of boules.

c) CdTe- -rectilinear features of microstructure, including crystals grown

in the furnace designed for space use.

d) Hgl 2

- -multigrained structure rotated around a common crystallographic

axis [110], and dendrite - like patterns along two orthogonal <100>

directions

.

e) ZnCdTe and HgCdTe (epitaxy) -- large strains in the epitaxial layers

that mask the structure of the substrate and interfacial regions.

High Resolution Radiography: Applications to Biomedical Imaging

R. Dobbyn and M. Kuriyama

In collaboration with S. Takagi and L. C. Chow, Paffenbarger Research

Center, American Dental Association, parallel beam microradiography with x- ray image magnification has been applied to dental hard tissues. This

technique was developed in the laboratory of the Synchrotron Radiation

Group and was applied to real time observation of dynamic phenomena in

alloys under heat treatment. The objective of the present application was

22
to ascertain the limit of spatial resolution in practice in the observation

of structural features within dental samples.

Some features which had been predicted to be less than 2 /i m are clearly

observed. There also are significant differences in the fine structure of

the lesion in microradiographs obtained at different x-ray energies. This

fact may be attributed to the crystalline nature of the microstructure.

Reconstruction of the History of Layering of Atoms During Crystal Growth

B. Steiner, M. Kuriyama, R. C. Dobbyn, U. Laor 1 and G. G. Long

1 Guest Scientist, Nuclear Research Center, Israel

Detailed analysis of synchrotron diffraction images of three slices from a single high quality boule of bismuth silicon oxide (optoelectronic

material) has led to an understanding of the origins of layering in the

deposition of atoms during crystal growth. The visibility conditions of

striations associated with layering as a function of diffraction index,

hkl, in the reflection and transmission geometries decipher a detailed

recording of periodic and aperiodic variation in the boule resulting from

interactions between the growing boule and the flow in the melt. Factors

identified for improved uniformity of such materials include: symmetry in

the solidification arrangement, reduction of fluctuations in rotations and

thermal stability, and chemical balance.

A New Oscillation Technique for Diffraction Imaging

B. Steiner, R. C. Dobbyn and M. Kuriyama

In contrast to white radiation Laue imaging, diffraction imaging with a monochromatic beam has much better sensitivity to crystal strains and

misorientations . However, if a sample is not oriented crys tallographically

beforehand, or has multiple grains, the application of this technique

becomes extremely difficult. When many samples must be assessed

systematically in a short time period, this difficulty discourages

materials scientists from the wide use of this high sensitivity and

quantitative technique. In this project, a new oscillation technique has

been developed to determine diffraction indices without prealignment and

regardless of grains in a sample crystal. Misorientation of grains can be

determined within less than 1/10 of a degree and twist axes of the

misorientation can be obtained accurately. After these quantities are determined, detailed information on strains and defects can be obtained

from each grain.

High Sensitivity and High Spatial Resolution Chemical Analysis

R. C. Dobbyn, D. R. Black and M. Kuriyama

In collaboration with Peter Pella, Center for Analytical Chemistry,

selenium has been identified in human and bovine blood sera at a level of 8 ppb through energy dispersive x-ray fluorescence. This high sensitivity

permits the determination of selenium at a level of 24 ppb in such systems

with a 10% standard deviation. This technique displays greater sensitivity

for the analysis of dilute solutions than previously obtained. Work to

23
extend the spatial resolution for the compositional mapping to 5 /^m is

being initiated with flat crystal optics for fluorescence detection.

X-Ray Monochromator Crystal That Detects the Bragg Condition

R. Spal

In collaboration with scientists from Center for Basic Standards and Center

of Electronics and Electron Engineering, the feasibility of a self -aligning

double crystal x-ray monochromator system has been demonstrated. An

experiment with synchrotron radiation has confirmed that the voltage

generated by a silicon crystal suitable for use in an x-ray monochromator

is extremely sensitive to extinction at the Bragg angle. This signal can

be used to orient a monochromator crystal quite accurately with respect to

the Bragg angle.

24
Figure 5. Indium doped Gallium Arsenide

Enlarged portion of a transmission topograph (040 diffraction) of a 800

micrometer thick indium doped gallium arsenide sample, R159-14 [CR2], taken at

10 kev on the NBS Materials Beam Line at NSLS . The central, faceted region of

the slice shown here is surrounded by a peripheral region of growth striations

characteristic of the growth. Other regions show the alignment of individual

dislocations, along with dislocation- free regions.
Enlarged portion of transmission topograph (022) diffraction) through an approximately 700 micrometer thick undoped gallium arsenide sample, GaAs

Al(100); [CG5], taken at 10 keV on the NBS Materials Beam Line at NSLS . Both

individual dislocations and their entanglement, seen as cellular boundaries at

lower resolution, are observed. This structure is char-acteristic of the

entire crystal and of the two other undoped gallium arsenide samples studied.

26
GLASS AND COMPOSITES Stephen W. Freiman

The Glass and Composite Group performs research in a number of areas, with

a particular emphasis on the mechanical properties of glasses,

polycrystalline ceramics, and ceramic matrix composites. There are major

efforts being undertaken in the study of: (1) environmentally enhanced

crack growth in brittle materials, (2) the effects of microstructure and

chemistry on the fracture of polycrystalline ceramics such as those used in

multilayer capacitors and the new superconducting ceramics (3) in the

understanding of the fracture behavior of fiber-reinforced, ceramic-matrix

composites. Data on the fracture behavior of brittle ceramics is needed in

order to use these materials reliably in components which may be subject to

mechanical or thermal stresses. Also, there is a considerable effort being

placed in the development of non-destructive evaluation procedures for

ceramics and ceramic matrix composites, with an emphasis on thermal wave

analysis. In addition, there is ongoing work related to the development of

glasses used as quantitative standards for elemental analysis. In all of

these areas, the Glass and Composites Group is undertaking cooperative

programs, both with personnel in other groups in the Ceramics Division, as well as with industrial and academic investigators in this country and

abroad.

Representative accomplishments

o Environmentally enhanced crack growth was observed in GaAs single

crystals for a variety of environments. These data have shown that

models of environmental enhancement of crack propagation based solely

upon bond ionicity are inadequate and must be extended. No

subcritical crack growth could be observed in Si for a wide variety of

chemical environments

.

o Using thermal wave techniques, thermal diffusivity (a) values were measured for a set of dielectric materials. The measurements have

shown that a can be determined reproducibly with an uncertainty of

less than 10% using the photoacoustic effect (PAE) . These results

have been obtained in a cooperative program with AVX, a capacitor

manufacturing company, which has provided samples for thermal,

electrical, and mechanical tests. This collaboration provides NBS

with custom made specimens to further research in dielectric ceramics

and provides AVX with valuable data for the evaluation of electronic

materials

.

o The first data on the fracture behavior of superconducting ceramics

has been obtained as a function of sintering and annealing conditions.

The sensitivity of this material to moisture enhanced fracture was established

.

o A fracture mechanics test procedure combined with a test designed to

determine the interfacial strength between a SiC filament and a glass

matrix were used to predict the effect of the filaments on retarding

c rack growth in ceramic matrix composites.

27
Environmentally Enhanced Fracture of GaAs and Si

G.S. White, S.W. Freiman, and A.M. Wilson1

1 Summer Student, Oberlin University

Cracks were propagated in single crystal specimens of GaAs in environments

with differing dielectric constants and chemical reactivities. Crack

growth behavior was also correlated with x-ray topographs of the GaAs

wafers. It was found that at least some of the strain patterns observed in

the topographs corresponded to residual stresses in the wafers. Water,

methanol and acetonitrile were observed to enhance crack growth in GaAs.

In contrast, no crack growth was observed in ammonia gas. These results

are at variance with a model which predicts that ammonia should be

effective and acetonitrile ineffective in enhancing crack growth in

materials whose bonds, like those in GaAs, are about 70% covalent in

nature. Results from both macroscopic crack growth measurement techniques

(double cantilever beam) and from microscopic techniques (indentation)

provided quantitative ranking of the effectiveness of different

environments in enhancing crack propagation with water being the most

effective and methanol being the least. No chemical environment has been

found which will promote crack growth in Si, which is 100% covalently

bonded.

Thermal Diffusivity Determination Using Photoacoustic Techniques

G.S. White and C. Nguyen1

1 Summer Student, University of Pennsylvania

In a cooperative effort of interest to the Navy, a set of barium titanate

based dielectric specimens were obtained from AVX Corporation, and both

Young's modulus, E, and thermal diffusivity, a, were measured at NBS . The

work has been valuable to AVX because they have received data important in

their evaluation of materials for electronics applications. E was measured

using standard ultrasonic pulse-echo procedures. a was determined by

fitting photoacoustic effect (PAE) measurements to a model in the

literature. From measurements on a known (alumina) specimen, the model was found to predict a to within 10%.

Fracture of Superconducting Ceramics

D.C. Cranmer, S.W. Freiman, M.L. Balmer

Initial experiments aimed at characterizing the fracture behavior of the new high Tc Ba2 YCU3 07

. x superconductors were performed. Both fracture

strength and fracture toughness were measured on samples sintered at 960°C

in either air or oxygen and annealed at 600°C in either air or oxygen.

Both the sintering and annealing environments were shown to affect strength

and toughness. The highest strength and toughness was observed in as- sintered material fired in oxygen. Upon annealing both the strength and

toughness dropped considerably. The fact that both Kx

c

and a show the same

28
trends indicates that the intrinsic properties of the material, not just

the flaw population, are affected by the processing conditions. In

addition, it was shown that moisture would enhance crack growth in these

materials as it does in most other ceramics.

Phase Transformation Toughening of Thallium Iodide (Tll)-ZnS

D.C. Cranmer and S.W. Freiman

One mechanism for toughening ceramic materials involves the use of phase

transformation toughening. This program is directed toward applying this

mechanism of toughening to infrared transmitting windows. Because of its

transmission in the 10-14 nM range, ZnS is a commonly used material in IR

transmitting applications, but has a lower than desired value of Kj c (1.0 MPam3* ) . Til has a phase transition involving a volume expansion which

occurs at 180°C, and a melting temperature of 440°C. Samples containing

between 10 and 30 volume % Til were prepared using reagent grade starting

powders which were ball milled, pressed, and sintered between 375°C and

500°C. An indentation technique was used to measure both the hardness and

the fracture toughness of the material. The best results were obtained

with samples containing 20 v/o Til. These samples were of low density

compared to chemically vapor deposited material so that better results are expected for higher density samples.

Crack Growth in Capacitors Under the Influence of Electrical Fields

D.C. Cranmer, S.W. Freiman, and S. Chen1

1 Summer Student, Duke University

A number of models exist in the literature which suggest that electric

fields can alter the stress field at crack tips in electros trictive

ceramics. Depending on the material, orientation, and field strength,

crack growth is either enhanced or inhibited. Crack lengths in the

presence of an electric field between 0 and 300 V were measured using an indentation technique on X7R capacitors. Results suggest that crack growth

in this material is inhibited by the presence of an electric field but that

the effect is small (less than 10% change in crack length). Additional

experiments are planned on materials having higher electrostrictive

coefficients

.

Fracture Behavior of Composites

T. W. Coyle 1

, U. Deshmukh2, T. R. Palamides 3

, W. Haller*1, S. W. Freiman

1 Processing Science Group,

2 Post Doc,

3 Graduate Co-op,

4 Research Associate

29
The fracture strength and stress-strain behavior of continuous - fiberreinforced ceramics is strongly influenced by the fiber/matrix interface.

A primary goal of this program is to relate the mechanical properties of

the interface to those of the composite. Special techniques have been

devised to coat AVCO SiC filaments (SCS-6) with a slurry of glass particles

and then quickly cure the slurry using high intensity ultraviolet

radiation. The coated filaments are laid up uniaxially in a mold and hot

pressed at 800 C to form composites containing ~25 volume percent of

fibers. The mechanical behavior of the interface between individual fibers

and the matrix has been characterized using a push out test. A special

fracture mechanics specimen has been utilized to determine the effect of

fibers in retarding crack growth.

30
PROPERTIES/PERFORMANCE
.

.
MECHANICAL PROPERTIES Sheldon Wiederhorn

Our program on mechanical properties has as its broad objectives: (1) the

generation of new theories and data to elucidate fracture and deformation

mechanisms in brittle materials; (2) the development of fracture

methodology for studying the fundamental forces that exist between two near

surfaces; (3) the investigation of ceramic microstructure and its

relationship to mechanical behavior; (4) the understanding of the

deformation and fracture properties that govern the mechanical response of

ceramics at high temperatures.

Representative Accomplishments

o A theory to explain the observed rising fracture toughness (R-curve)

of monophase ceramic materials with growing crack size has been

further developed. The source of the toughness of ceramic materials

originates in interlocking grains and unbroken ligaments that cross between the crack faces. These apply a closure force to the crack

that must be overcome for fracture to proceed. This theory implies

that the toughness of ceramic materials can be enhanced by

microstructural design to increase the degree of interlocking of

fracture surfaces. Materials are currently being fabricated to

optimize the toughness characteristics.

o The role of surface forces in subcritical crack growth has been

explored for ceramic materials. Surface forces can account for a number of physical observations including the healing of cracks when

the external driving forces are removed, and the presence of fatigue

limits. These predictions are being investigated through experimental

studies on mica, glass, and sapphire. A theoretical model of the role

of surface forces has been developed.

o Creep in tension and compression have been shown to be unequal in high

temperature structural ceramics suggesting the necessity for

collecting creep data in both tension and compression for reliable

design at elevated temperatures.

o A transient stress analysis has been obtained to characterize the

creep behavior of structural components that are subjected to complex

load configurations. The analysis technique has been applied to

flexure specimens subjected to four-point bending, and to c-rings

subjected to compressive loading. Asymmetric creep behavior was incorporated into the analysis.

Microstructure and Toughness

B.R. Lawn, S.J. Bennison1

, and H.M. Chan1

1 Guest Scientist, Lehigh University

During the past year the strength behavior of a number of ceramic materials

has been studied using indentation flaw techniques. Crack growth from the

indentation flaws was recorded on a video tape recorder so that the

31
qualitative aspects of the intrinsic fracture resistance could be

documented. The results suggest that interlocking grains and ligaments of

unbroken material in the wake of the crack front serve to apply a closure

force to the crack surface which must be overcome for the crack to

propagate. Based on the above observations, a model of crack growth has

been developed for predicting strength as a function of microstructure.

The output of this project has strong implications concerning the

microstructural tailoring required for optimum toughness properties of

ceramics. A collaborative program with Dr. M.P. Harmer's ceramics

processing group at Lehigh University is currently underway to explore this

prospect. Monophase composites" are being made with duplex grain

structures to provide maximum resistance to crack growth.

Surface Forces

B.R. Lawn, S. Lathabai 1

, and R.M. Thomson

1 Guest Scientist, Lehigh University

In addition to the covalent and ionic cohesive forces that hold brittle

materials together, there are weaker (but longer-ranged) adhesive forces

which come into play when new surfaces are created, particularly in the

presence of interactive environments: dispersion (van der Waals) , electric

double layer, solvation and cation-site forces are examples. These are the

surface forces which are of such great importance in colloidal chemistry.

We have shown in fracture experiments on mica, glass and sapphire that

forces of this type are important also in strength properties of ceramics.

They bear on the reversible nature of crack growth (i.e. crack healing),

and hence on the existence of a "fatigue limit," i.e. an applied stress

level below which propagation ceases. This interrelation between surface

closure forces and crack properties is leading to a fundamentally new

conception of fracture, whereby the underlying processes of bond rupture at

the crack tip operate independently of the adhesive processes behind the

tip. Scientifically, the decoupling of the two processes provides impetus

for study on crack- tip structures at the atomic level. More importantly,

it offers a potential new technique for measuring surface forces using

fracture. We have obtained experimental data on mica and other brittle

ceramics, and have developed a theoretical model that relates the fracture

behavior to surface force functions that can be measured by independent

means

.

High-Temperature Deformation and Fracture

S.M. Wiederhorn, T.-J. Chuang, B.J. Hockey, D.E. Roberts and D.F. Carroll 1

1 Guest Scientist, The Pennsylvania State University

The development of new ceramics provides hope for high efficiency, enhanced

performance of structural systems in high temperature, stress -bearing

environments. However, before ceramics can be used in industrial

applications, issues concerning reliability and service life remain to be

32
resolved. With this in mind, we have been studying the creep and creep

rupture behavior of model ceramics at elevated temperature.

During the past year the creep behavior of a commercial grade of reaction

bonded silicon carbide was characterized at a temperature of 1300°C. Creep

occurred more easily in tension than in compression. At a given applied

stress, the steady state creep rate in tension was found to be at least

twenty times that obtained in compression. In both tension and

compression, the stress exponent for steady state creep was found to

increase with increasing applied stresses. At low applied stresses, the

stress exponent was ~4 , suggesting some kind of dislocation mechanism as a controlling factor in the creep of the two-phase composite. At high

stresses, the stress exponent was =11. In tension, the increase in the

stress exponent was attributed to damage accumulation in the form of

cavities. An effective threshold stress for cavitation of less than 100

MPa was suggested. In compression, however, the cause of the increase of

stress exponent with stress cannot be attributed to cavitation. A simple

model has been proposed which is capable of describing all major features

of the asymmetric creep. Data collected on this material are now being

used to analyze distributions of stress and strain in ceramic components

used in heat exchangers and in radiant heaters. During the coming year,

data similar to these will be collected on other structural ceramics.

A new effort has been initiated to study the mechanical behavior of ceramic

interfaces at elevated temperatures. Interfaces will be formed by the

joining of ceramic materials at elevated temperatures, and the structure of

these interfaces will be characterized by techniques of transmission and

scanning electron microscopy. Once interfaces can be made in a reproducible manner, their strength and creep behavior will be studied

under both normal and shear loads. Data obtained on this program will be

used to characterize the mechanical behavior of ceramic joints in high

temperature structural components.

33
'

.
TRIBOLOGY S. Jahanmir

Tribology is the science that deals with friction, lubrication and wear of

interacting surfaces that are in relative motion. A prototype tribological

contact consists of two solid bodies, separated by a thin film of

lubricant, in a relative sliding motion; such as a bearing. This seemingly

simple system is extremely complex and requires knowledge from several

disciplines, such as materials science, physics, chemistry and engineering.

The primary objectives of the Tribology Group are: 1) development of new

theories and data to elucidate the complex reactions that occur between

sliding surfaces and the environment, 2) exploration of mechanisms of

friction, lubrication and wear of advanced ceramics, 3) establishment of

test techniques and procedures for evaluating the performance of new

materials, 4) generation of wear maps for materials to elucidate the effect

of operating variables on performance, and 5) establishment of a computerized information system for tribology to be used for technology

transfer

.

Representative Accomplishments

o A time-resolved micro-Raman test system was developed to analyze

chemical reactions at tribological contacts. The system uses a Nd-YAG

laser to provide periodic pulses of monochromatic light which are focused on the tribocontact of a specially designed wear tester. This

unique facility can provide fundamental knowledge on complex chemical

reactions

.

o The elucidation of chemical reactions between advanced ceramics and

synthetic lubricants using a combination of tests showed strong

chemical interactions between synthetic esters and alumina surfaces

.

Although the reaction products are essential for friction reduction,

they may contribute to corrosive wear.

o Test results on alumina, silicon nitride and silicon carbide

lubricated with mineral oil have shown that at a specific load both

the friction coefficient and the wear rate increase to a level

comparable with the data in unlubricated tests.

o Development of data to establish wear maps for advanced ceramics was initiated in conjunction with the Center for Advanced Materials at the

Pennsylvania State University under the sponsorship of the Gas

Research Institute. Wear maps for several advanced ceramics have been

generated.

o The first public demonstration of a prototype model of A Computerized

Tribology Information System (ACTIS) was successfully demonstrated.

This paves the way for future effective technology transfer and

potentially could save billions of dollars annually for U. S. industries

.

35
In-Situ Analysis of Chemical Reactions

B.E. Hegemann and S. Jahanmir

The understanding of tribochemical reactions that control friction and wear

has eluded researchers, partly because of the inability to observe the

reactions in-situ and partly due to the inability to analyze the end

results in a manner that would lead to the development of accurate models

of the chemistry in the tribocontact zone. A time-resolved micro-Raman

laser system was developed to elucidate tribochemical reactions occurring

in the contact zone in real time. The system uses a Nd-YAG laser to

provide periodic pulses of monochromatic light which are focused on the

tribocontact of a specially designed wear tester. The scattered light is

collected by specially designed optics and recorded by a gated intensified

diode array detector. The detector system is governed by a device

specified controller.

Ceramics Lubrication

J. M. Perez, C. S. Ku, P. Pei, L. S. Hsu and S. Jahanmir

The tribochemical reactions between several synthetic lubricants and

ceramic substrates have been analyzed using unique facilities developed at

NBS, which elucidate the chemical composition of surface films formed at

tribological contacts. Results to date include.: 1) differences were found

in the rate of reaction of some synthetic lubricants with a-alumina.

Although both a synthetic hydrocarbon and a polyol ester show good friction

characteristics in the wear tests, decomposition products from the ester

interact more readily with the substrate leading to a possible corrosive wear mechanism, and 2) two synthetic lubricants, a phosphate ester and a polyether both produce polymeric type reaction products which may be

important to high temperature lubrication of ceramics.

Friction and Wear Measurements for New Materials and Lubricants

D.E. Deckman, R.S. Gates, J.P. Yellets, S. Jahanmir, and T.C. Ovaert

Ceramics are being considered for a wide range of applications in advanced

heat engines that require high temperature performance. The research

activities have focused on the selection of appropriate test apparatus,

contact geometry, specimen preparation procedure, and assessment of the

effect of test variables on friction and wear performance of several

advanced ceramics. Test results on alumina, silicon nitride and silicon

carbide, lubricated with mineral oil have shown that at a specific load

both the friction coefficient and the wear rate increase to a level

comparable with the data in unlubricated tests. The fundamental mechanisms

which control this transitional behavior are currently under investigation.

To enable studies over a wider temperature range, two test apparatus have

been developed to study friction, wear and lubrication characteristics of

advanced ceramics. This facility was designed for temperatures up to 1500

degrees Celsius under controlled-atmospheres

.

36
Wear Maps for Advanced Ceramics

R

.

G . Munro and D . S . Lim1

1 Guest Scientist, University of Illinois

A comprehensive assessment was conducted on the tribological issues,

research needs and priorities of ceramic materials relevant to engines

fueled by natural gas. The assessment included a review of the technical

literature, an appraisal of published data, and in-depth interviews and

site visits to selected industrial research groups. The review concludes

that data are needed in four general areas: performance, wear prediction,

surface reactivity, and surface strength.

Advanced ceramic materials provide the key to developing high efficiency

engines for which materials having high temperature stability, durability,

and wear resistance are required. Data, design criteria, and an understanding of the effects of combustion products on the wear of

materials are especially needed before ceramics can be fully utilized in

advanced technology engines. Consequently, an effort was initiated to

define the limits and requirements of ceramics under various conditions of

speed, load, temperature, and environmental factors. These data are expected to provide a critical step towards understanding the wear

mechanisms of advanced materials and the establishment of predictive models

of wear.

A Computerized Tribology Information System

S. Jahanmir, R.G. Munro and S. Danyluk1

1 IPA, University of Illinois

Research in tribology is attempting to reduce the estimated $100 billion

cost incurred by the U. S. economy each year as a result of friction and wear processes. The Department of Energy has estimated that as much as forty percent of those losses could be saved by improved technology

transfer. Research in tribology, however, is a complex, interdisciplinary

effort that involves scientists and engineers of rather diverse areas of

expertise. These researchers report their progress in correspondingly

diverse media. As a result, advances in this field are often hindered by

the inaccessibility of critical data or by the lack of awareness of

parallel and concurrent research efforts.

An international effort to overcome this technological problem is being

pursued through the development of A Computerized Tribology Information

System (ACTIS) . The central project, ACTIS , is an interagency government

program sponsored by the Department of Energy/Energy Conversion and

Utilization Technology/Tribology Program, the National Bureau of Standards,

the U.S. Army/Fort Belvoir, the U. S. Air Force/Wright Patterson

Aeronautical Laboratories, and the National Science Foundation. Additional

support is being provided by the American Society of Lubrication Engineers,

by the American Society of Mechanical Engineers, and by two distinguished

advisory committees.

37

OPTICAL MATERIALS Albert Feldman

The objective of the Optical Materials Group is to provide data,

measurement methods, standards and reference materials, concepts, evaluated

data, and other technical information on the fundamental aspects of

processing, structure, properties and performance of optical materials for

industry, government agencies, universities, and other scientific

organizations. The program supports generic technologies in crystalline,

glassy, and thin film inorganic optical materials in order to foster their

safe, efficient and economical use. Research in the group addresses the

science base underlying new advanced optical materials technologies

together with associated measurement methodology.

The principal area of optical materials research being covered is thin

optical films , which addresses the processing/structure relationships of

diamond and other ceramic coating materials and how they affect properties

and optical performance as related to optical coatings and integrated

optics

.

Representative Accomplishments

o A diamond film deposition and characterization activity was begun. A

diamond film deposition apparatus has been constructed and diamond

films have been deposited. Structure in the films has been verified

to be diamond as determined by x-ray diffraction, Auger electronspectroscopy, electron energy loss spectroscopy, and Raman

spectroscopy. Scanning electron microscopy indicates a significant

surface roughness.

o The x-ray photoelectron spectra of the oxygen Is and silicon 2p levels

in films in the SiOx system have been examined. Films prepared by

reactive evaporation of Si in a partial pressure oxygen show silicon

clusters and unincorporated oxygen. The composition of the remainder

of the material agrees qualitatively with the random bond model (RBM)

.

o The photothermal radiometry signal vs chopping frequency from plasma

sprayed films of zirconia and chromia has been fit to a mathematical

model and values for thermal diffusivity and thermal conductivity have

been obtained as a means for monitoring the quality of ceramic

coatings. The thermal conductivities of the coatings appear to be two

to five times smaller than the thermal conductivities of bulk

materials

.

Thin Optical Films

A. Feldman, E. N. Farabaugh, and Y. N. Sun1

1 Guest Scientist, Lanzhou Institute of Physics, Lanzhou, Peoples Republic

of China

Diamond Films : The Optical Materials Group has begun an activity in

diamond film research. The emphasis has been on the deposition of diamond

39
films and identification of the diamond phase by a variety of methods. The

electron-assisted CVD deposition method was chosen for its simplicity and

for scale-up possibilities. Typical deposition parameters were: gas

mixture, 0.47% methane, remainder hydrogen; flow rate, 50 seem; deposition

pressure, 40 torr; filament temperature, 1800°C (approx); substrate

temperature range, 700°C; filament emission current, 0 to 10 ma.

Our first successful depositions were made on silicon wafer substrates.

The deposited material consisted of crystalline particles having polyhedral

shapes typical of the diamond particles described in the literature.

Subsequently, we were able to deposit these particles on sapphire and

silica as well. The size of the particles, as measured by SEM, were typically 3-10 ^m. Micro-Raman spectra were obtained from individual

particles by Edgar Etz of the Gas and Particulate Science Division. A

sharp Raman line with very little background, centered at 1322 cm' 1 which

is 10 cm" 1 below the Raman line of natural diamond, was observed. A

measurement by Bob Nemanich of North Carolina State University on one of

our later films showed the diamond line at 1331 cm" 1 as expected. In

addition, the latter spectrum showed a fluorescent background and

additional graphitic- like structure near 1350 cm" 1

. These results are typical of the best films he has measured. In order to deposit continuous

films, we found it necessary to scratch the substrate surface with diamond

paste

.

X-ray diffraction measurements were made both with a Read thin-film

diffraction camera and with a powder diffractometer. A one-to-one

correspondence between the diffraction lines in natural diamond abrasive

powder and the diffraction lines in the film was found. The lattice

spacings of the film agree well with the lattice spacings of natural

diamond

.

Both our diamond films and graphite powder have been examined by Auger

electron spectroscopy and by electron-energy loss spectroscopy. Based on

the published results for bulk diamond and graphite, both sets of spectra

confirm that our films are diamond.

Thin Film Stoichiometry : X-ray photoelectron spectroscopy (XPS)

measurements of the 0 Is and Si 2p lines in films of the SiOx system have

been interpreted on the basis of the random network model. Fitting of the

spectra to five lines corresponding to five silicon centered tetrahedral

configurations yield the relative proportion of each tetrahedron in the

film. The distributions agree neither with the random mixture model (RMM) nor with the random bond model (RBM) . The total oxygen in the films

exceeds the amount of oxygen in the tetrahedral structures indicating the

presence of molecular oxygen, water, peroxy bonding or other forms of

oxygen not bonded to silicon. The general features of the distributions

can be explained on the basis of silicon clusters, unincorporated oxygen

and the RBM

.

40
Photothermal Radiometrv for Monitoring of Ceramic Film Quality

H. P. R. Frederikse, A. Feldman, and X. T. Ying1

1 Guest Scientist from Fudan University, Shanghai, Peoples Republic of China

We have applied the method of photothermal radiometry to determine the

thermal behavior of two different oxide coatings: chromia and partially

stabilized zirconia, both deposited on aluminum plates. The oxide coatings

were produced by arc plasma spraying in thicknesses ranging from 61 Mm to

152 /im. A least squares method was used to determine the photothermal

parameters which in turn yielded the values for thermal diffusivity and

thermal conductivity. Table 1 lists the values obtained for both the

chromia and the zirconia samples. In the last column we have listed some thermal conductivity figures quoted in a recent data handbook' The

handbook values cover a large range because the thermal conductivity even

of bulk ceramics depends strongly on the density, grain size, and purity of

the material. Our measured results for plasma sprayed coatings appear to

be at the lower end or just below the Handbook values. The considerable

variation in magnitude confirms our expectation that the thermal properties

of plasma sprayed coatings are strongly affected by the deposition

procedures and conditions. It is quite possible that the thermal

conductivity depends more on the contact resistance between the grains than

on the conduction through the grains. The thermal wave method appears to

have considerable potential for testing the thermal behavior of coatings.

Because it is a non-contact technique, its use as an in- situ measurement at

high temperatures appears to be practical.

Table 1. Summary of Thermal Diffusivities and Thermal Conductivities

Sampl e thickness

(Mm)

thermal

diffusivity

(cm2 /sec)

thermal

conductivity

(W/cm deg)

thermal

conductivity

[Handbook*]

^ r2^3 #1 100 0.013 0.0835 0.10 - 0.33

#2 150 0.014 0.0695

Cr2 03 III 90 0.025 0.082

Cr2 03 IV 125 0.015 0.063

Zr02 A 60 0.017 0.007 0.018 - 0.022

(partially stabilized)

Zr02 B 97 0.017 0.012 0.0069 - 0.024

(plasma sprayed)

* "Ceramic Source '86" (Am. Ceramic Soc . ) , pp . 350- 351

.

41
'

.
COMPUTERIZED DATA ACTIVITIES GROUP Camden R. Hubbard

A rapid increase in new applications of advanced ceramics depends to a great extent on providing design engineers and research scientists with

reliable and timely data compilations. The objective of the Computeri-zed

Data Activities Group is to meet this need in the fields of phase

equilibria and materials properties of high technology ceramics. There are three subtasks within the Group: the Ceramic Phase Diagram Program; Phase

Equilibria and Crystal Chemistry; and Ceramic Property Data.

The largest subtask is the Ceramics Phase Diagram Program which is

conducted jointly with the American Ceramic Society. Closely related is

the experimental Phase Equilibria and Crystal Chemistry subtask. These two

activities are coupled to the measurement and prediction of x-ray powder

diffraction reference patterns, a subtask within the Powder

Characterization Group. The newest subtask is the assessment of needs for

and initiation of activities leading to a national ceramic properties

database system.

A materials property data program is of importance to our country's ability

to introduce advanced ceramics competitively in the rapidly growing

international advanced ceramic market. The activities of the last year

focused on assessing the needs and opportunities in this field.

Considerable encouragement has been received from the Gas Research

Institute and from industrial representatives. Plans are to further

emphasize this activity by expanding NBS ' role in this field.

Representative Accomplishments:

o Completed evaluation, database entry and typesetting of Volume 6 of

Phase Diagrams for Ceramists . This is the first evaluated data

compilation from the NBS managed Ceramic Phase Diagram Program.

o Developed and exhibited at ACerS meetings a personal computer

prototype phase diagram graphics package.

o Developed an oxide phase equilibria predictive capability which

permits extrapolation into regions where experimental data are sparse

and projection of isothermal surfaces and/or constant composition

cross sections is required.

o Reported the structure, crystal chemistry, and x-ray powder

diffraction reference patterns of the Ba0-Y2 03 -Cu0 high Tc superconductor phase.

o Determined the phase equilibria relationships in the Ba0-Y2 03 -CuOx system in air near 900 C, and outlined the primary phase field of the

superconducting phase.

o Evaluated the phase stability of the high Tc superconductor material

in contact with potential container materials.

43
o Assessed the needs for, materials to include, properties of interest,

and service conditions for inclusions in a ceramic materials property

database covering applications involving use of natural gas.

Ceramic Phase Diagram Program

C. R. Hubbard, H. M. Ondik, R. S. Roth, M. A. Clevinger, P. K. Schenck1

, L.

P. Cook1

, J. H. Hastie 1

, J. Dennis2, T. Brittle2, J.-O. Anders s on2, C. Messina2

, H. F. McMurdie2

, S. Cauley3, P. O'Neil3, M. Rodtang3, D. Pennington3

, R. Wilson3

, and R. Yang3

.

1 High Temperature Chemistry Group

2 Research Associate, American Ceramic Society

3 Student Research Associate, American Ceramic Society

The National Bureau of Standards (NBS ) -American Ceramic Society (ACerS)

ceramic phase diagram program completed its second full year of the

expansion plan. This joint program is the response to industry's growing

need for broad coverage of ceramic systems and a more current, evaluated

data compilation. The need for these data is evidenced by industrial

contributions of nearly $2,000,000 to support Research Associates at NBS

who are responsible for the production of both computer databases and

printed compilations.

(a) Phase Diagram Evaluation and Production . The first evaluated data

output from the program, Volume 6 of Phase Diagrams for Ceramists , was completed and turned over to ACerS for printing. This volume contains 697

commentaries and 1080 binary, ternary and higher order phase diagrams of

oxides, metals plus oxides, and metals plus oxygen. The completion of this

Volume, produced using computer graphics and database systems, is a major

milestone which sets the stage for numerous outputs of the Data Center.

(b) Database Development . The production of Volume 6 demonstrated

application of all aspects of the database system and software established

over the last two years. The most recent program addition was graphics

entry procedures for ternary and partial diagrams. The commentary and

bibliographic database software was fully tested and refined. The computer

typesetting of the commentaries and indexes for Volume 6 was completed

using recently completed software. The composition system operator has

only to perform pagination and insertion of page headings.

(c) Computer Database Dissemination . To investigate means to enhance

dissemination, two personal computer (PC) projects have reached the

demonstration stage. A PC graphics package, which combines software and a graphics database, was exhibited at the ACerS Annual Meeting. This package

permits the user to display any diagram from our database on a PC, to

magnify regions (see Figure 6), to overlay related diagrams, to perform

lever rule calculations, to display the cursor position in real units of

the diagram, and to select the temperature scale. A second PC package

demonstrated the successful transfer of commentary and chemical system data

files from a minicomputer to a PC database management system and produced a comprehensive, PC searchable file.

44
(d) Mode ling /Optimization . The Thermo-Calc program, developed at the Royal

Institute of Technology in Stockholm, has been installed at NBS

,

successfully tested, and used to assess the role such modeling programs can play in the evaluation and dissemination of phase diagrams. Of great

interest is the ability to generate particular cuts through high order

diagrams (e.g. isothermal cuts of a ternary or higher order system). The

program can be used to also predict approximate diagrams for systems with

limited experimental data. Application to binary and ternary systems

containing BaO , Ti02 , Al 2 03 , and MgO have shown good agreement with known

diagrams and thermodynamic data.

Phase Equilibria and Crystal Chemistry

R. S. Roth, J. Dennis, K. Davis 1

, J. Whitler1, R. J. Cava2

, H. Parker3

, P. K. Davies 4

, W. Wong-Ng5

1 Student

2 Guest Scientist, AT&T Bell Laboratories

3 Guest Scientist, NBS

4 Guest Scientist, University of Pennsylvania

5 Guest Scientist, University of Maryland

Phase equilibria data supply fundamental information for the understanding

of processing and stability of ceramics. This subtask focuses on measurement of the phase equilibria of important advanced ceramic systems

such as microwave dielectric ceramics and the new oxide high Tc superconductors. Fundamental predictive information is developed from

detailed crystal chemical and lattice defect information.

(a) Ba0-Y2 0 3 -CuO Superconductor System . Preliminary phase equilibria

diagrams were determined and reported for the three binary systems and the

ternary system (Figure 7) . Melting point data were used to outline the

primary phase field, the composition region where single crystals of the

Ba2 YCu3 0 7

_ x superconductor (2:1:3) can be grown. The crystal chemistry of

this phase was determined using neutron Rietveld analysis methods (see

cover) ; X-ray powder diffraction reference data for the phases of this

system were also reported.

(b) Container Reactions with melts in the BaO-Y2 Q3 -CuO System

Starting materials in the Ba0-Y2 03 -CuOx system are very reactive and

corrode most common container materials potentially used in phase

equilibria work and potentially processing. Experiments were conducted to

test a Ag-Pd alloy, and preliminary results indicate that the alloy does

not interact with the samples. Containers of this alloy were used to

determine the melting relations near the 2:1:3 superconductor phase.

45
Ceramic Property Data

C. R. Hubbard

In collaboration with the Gas Research Institute, an assessment of the

current status of computerized materials properties databases was conducted. The study found only nine mature and developing public domain,

numerical, computerized data bases. Comparing essential design properties

for selected gas fired applications with the coverage of these nine

databases revealed very little overlap with the property data needs of

design engineers. Identified barriers to developing a ceramics property

database include materials specification, standardized test methods, and

development of a database management system for scientific data. To

address the first barrier, the task group on Specification of Ceramics of

ASTM E49 , on Computerization of Materials Property Data, met at NBS to

focus on potential options.

46
KBS/ACe^S PDFC: FI&378 .BP1

ficl A

Orij

Axes

S3.5&4 1448. 8e*C H for Help

Figure 6 . Copies ci PC screens iron rhe prototype PDFC graphics

a) The S iC2 -3a2 S i, 0 £ binary diagram b) Section of the sane dia

magnification. Readout of the cursor position (+) , in real uni

diagram, is shown at the lower left. A user-friendly help screen

of options available to the user is obtained by pressing the H ke

system

.

consisting

47

(I

(Cl
BaO

r igure 7. Phase diagram for the BaO-Y2 03 -CuOx system in air near 900 C. xhe high Tc superconductor phase is labeled 2:1:3. The region where single

crystals can be grown from a melt is the primary phase field.
RESEARCH STAFF

PROCESSING

Ceramic Powder Characterization

Cline, James P.

Dragoo , Alan L.

Kelly, James F.

Long, Gabrielle

Minor, Dennis B.

Robbins, Carl R.

Processing Science

o X-ray diffraction of ceramics

o Quantitative analysis

o Characterization of ceramic precursor

powders

o X-ray characterization

o A-C spectroscopy

o Scanning electron microscopy

o Image analysis

o A-C spectroscopy

o Small angle neutron scattering

o Small angle x-ray scattering

o Analytical SEM of ceramics and

particulates

o Powder test sample preparation

o High temperature ceramic synthesis

o Ceramic powder characterization

o Spray drying; powder preparation

o Quantitative microscopy and x-ray

diffraction

o NDE of ceramics

Blendell, John E.

Block, Stanley

Coyle, Thomas W.

o Ceramic processing and clean-room processing

o Sintering and diffusion controlled processes

o Processing high Tc ceramic superconductors

o Activation chemical analysis

o Ceramic processing and high-pressure

sintering

o Pressure- induced transformation toughening

o High-pressure physical properties &

structures

o High-pressure X-ray diffraction and

spectroscopy

o Processing/microstructure/fracture relations

o Toughening mechanisms in ceramics

o Processing and properties of ceramic

composites

o Stress induced transformations

49
Fuller, Edwin R. Jr.

Harding, Chester A.

Krause, Ralph F. Jr.

Ostertag , C . P .

,

Dr

.

Piermarini, Gasper J.

Stearns, Laura C.

Vaudin, M . D .

,

Dr

.

Ceramics Chemistry and

Blair, William R.

Brinckman, Frederick

Coyle, Thomas D.

o Atomistic models of fracture and grain

boundaries

o Processing and properties of ceramic

composites

o Toughening mechanisms in ceramics

o Processing high Tc ceramic superconductors

o Ceramic processing and sintering

o Hot pressing

o Ceramic fabrication

o Fracture mechanics of ceramics

o Creep of ceramics and high- temperature

measurements

o Chemical thermodynamics

o Influence of heterogeneities on sintering

o Processing and sintering of reinforced

ceramics

o Ceramic processing and high-pressure

sintering

o Pressure- induced transformation toughening

o High-pressure physical properties &

structures

o High-pressure X-ray diffraction and

spectroscopy

o Ceramic processing and sintering

o Electronic properties of ceramics

o Microstructural properties of ceramics

o Microscopy and diffraction of interfaces

Bioprocesses

o Ultratrace metals speciation

o Biotransformations of metals

o Environmental durability of coatings

o Molecular surface characterization

E. o Environmental metal transport

o Organometallic chemistry

o Biological mediation of surface chemistry

o Ultratrace metal speciation

o Inorganic and organometallic chemistry

o Chemistry of materials processing and

durability

o Low temperature synthesis of ceramic

powders

o Chemistry of ceramic precursor materials

50
Faltynek, Robert A.

Jewett, Kenneth L.

Olson, Gregory J.

Parks , Edwin J

.

Rhyne , Kay A

.

Ritter, Joseph J.

o Inorganic molecular synthesis

o Surface and solution photochemistry

o Spectrophotometry

o Heterogeneous catalysis

o Redox kinetics of heterogeneous systems

o Organometallic speciation

o Abiotic transformation of metal species

o Analysis of organic mixtures

o Metals biotransformation

o Bioprocessing industrial materials

o Epif luorescence microscopy imaging

o Surface modification and bioadhesion

o Metalloorganic synthesis

o Macromolecular organometallic chemistry

o Metals imaging in coatings

o Ultratrace metal speciation

o Biological transformation of inorganic

materials

o Ceramic processing

o Neutron scattering

o Nondestructive analysis

o Colloid and sol-gel chemistry

o Synthetic inorganic chemistry

o Ceramic powders from organometallic

precursors

o Ceramic powders from gas phase, and

solution precipitation reactions

51
Ceramics Chemistry and Bioprocesses

Blair, William R.

Brinckman, Frederick E.

Coyle, Thomas D.

Faltynek, Robert A.

Jewett, Kenneth L.

Olson, Gregory J.

Parks , Edwin J

.

Rhyne , Kay A

.

Ritter , Joseph J

.

o Ultratrace metals speciation

o Biotransformations of metals

o Environmental durability of coatings

o Molecular surface characterization

o Environmental metal transport

o Organometallic chemistry

o Biological mediation of surface chemistry

o Ultratrace metal speciation

o Inorganic and organometallic chemistry

o Chemistry of materials processing and

durability

o Low temperature synthesis of ceramic

powders

o Chemistry of ceramic precursor materials

o Inorganic molecular synthesis

o Surface and solution photochemistry

o Spectrophotometry

o Heterogeneous catalysis

o Redox kinetics of heterogeneous systems

o Organometallic speciation

o Abiotic transformation of metal species

o Analysis of organic mixtures

o Metals biotransformation

o Bioprocessing industrial materials

o Epifluorescence microscopy imaging

o Surface modification and bioadhesion

o Metalloorganic synthesis

o Macromolecular organometallic chemistry

o Metals imaging in coatings

o Ultratrace metal speciation

o Biological transformation of inorganic

materials

o Ceramic processing

o Neutron scattering

o Nondestructive analysis

o Colloid and sol-gel chemistry

o Synthetic inorganic chemistry

o Ceramic powders from organometallic

precursors

o Ceramic powders from gas phase, and

solution precipitation reactions

52
STRUCTURE/STABILITY

Glass and Composites

Balmer, Mari Lou o Mechanical Property Testing

o Fiber processing

Blackburn, Douglas H. o Special glass formulations

o Glass processing

o Glass standards for microprobe analysis

Cellarosi, Mario J. o Glass SRM development

o Glass standards for manufacture and use

o Glass property measurements

Chiang, C. K. o Electronic ceramics

o Superconductivity

Cranmer, David C. o Composites

o Glass viscosity

o Fracture

Freiman, Stephen W. o Ceramics and glasses

o Electronic ceramics

o Mechanical properties, environmental

effects

o Composites

Kauffman, Dale o Glass processing

o Viscosity measurements

White, Grady S. o Ceramics and glass

o Nondestructive evaluation

o Subcritical crack growth

High Temperature Chemistry

Bonnell, David W. o High Temperature -pressure mass spectrometry

o Computer modeling

o Levitation calorimetry

Cook, Lawrence P. o Phase equilibria of ceramics (modeling

and experiment)

o Phase diagrams for ceramists data center

o Electron microscopy

o Thermodynamics

Davidson, Paula M. o Phase equilibria models

o Thermodynamics

53
Hastie , John W. o High temperature chemistry of ceramics

o Ceramic phase equilibria and solution

models

o High temperature-pressure mass spectrometry

o Chemistry of combustion

Plante, Ernest R. o High temperature chemistry of ceramics

o Knudsen effusion mass spectrometry

o Vaporization thermodynamics

Schenck, Peter K. o Laser spectroscopy

o Temperature measurement

o Computer graphics

Synchrotron Radiation

Black, David R. o Inelastic x-ray scattering

o Energy dispersive diffraction

o Fluorescence and absorption

Burdette, Harold E. o X-ray optics engineering

o Crystal growth

o Instrumentation

Dobbyn, Ronald C. o X-ray imaging

o X-ray optics

o Microradiography

Kuriyama, Masao o Scattering physics

o Condensed matter physics

o Crystallography

Spal , Richard D. o X-ray optics

o X-ray image detectors

o Condensed matter physics

Steiner, Bruce W. o X-ray diffraction imaging

o Optoelectronic materials

o Crystal growth

54
PROPERTIES/PERFORMANCE

Mechanical Properties

Chuang, Tze-jer

Hockey, Bernard J.

Lawn, Brian R.

Wiederhorn, Sheldon M.

Tribology

Hegemann, Bruce E.

Hsu, Lin-Sien

Jahanmir, Said

Ku, Chia-Soon

Munro , Ronald G.

Pei, Patrick

o Ceramics

o Diffusional crack growth

o Finite element analysis

o Creep theory

o Ceramics

o Scanning and transmission electron

microscopy

o Interfaces

o Microstructure

o Microstructure/strength relations

o Fracture mechanics

o Contact phenomena

o Surface forces in fracture

o Ceramics

o Fracture

o Reliability

o Creep rupture

o Time -resolved micro-Raman spectroscopy

o Micro-FTIR spectroscopy

o Laser- induced fluorescence spectroscopy

o Lubricant volatility and oxidation stability

o Lubricant fractionation

o High temperature lubrication

o Wear mechanisms

o Boundary lubrication

o Mechanical behavior of materials

o Lubrication of ceramics

o Lubricant oxidation, thermal stability and

volatility

o Lubricant degradation mechanisms

o Theory and modeling

o Molecular dynamics of phase stability

o Temperature modeling of ceramic pairs

o Characterization of lubricants and

lubrication products

o Separation of complex organic mixtures

o Trace organic compound identification

55
Perez, Joseph M. o Additive chemistry and deposits

o Thermal and oxidation stability of fluids

o Fuels, lubricants and diesel engines

Optical Materials

Farabaugh, Edward N.

Feldman, Albert

o Thin film deposition and analysis

o X-ray diffraction analysis

o Scanning electron microscopy

o Surface analysis

o Diamond films

o Superconducting films

o Optical films

o Guided waves

o EXAFS

o Diamond films

o Superconducting films

Frederikse, Hans P. R. o Thin film thermal wave analysis

Computerized Data Activities

Dennis, Jennifer

Hubbard, Camden R.

Ondik, Helen M.

Roth, Robert S.

o Phase equilibria of ceramics

o Electron microprobe

o Phase diagram evaluation

o X-ray microstructural characterization

o Reference data for ceramics

o Crystal structure and chemistry

o Database management

o Phase diagrams for ceramists

o Materials properties data

o Database management systems

o Crystal chemistry of ceramics

o Phase equilibria

o Dielectric and electronic ceramics

o Phase Diagram evaluation

56
GUEST SCIENTISTS AND GRADUATE STUDENTS

Andersson, J.-O., Dr. Royal Institute of Technology, Stockholm

Bailey, David R. The Pennsylvania State University

Baker, Theresa L. , Ms. Ohio State University

Bennison, S.J., Dr. Lehigh University

Blakemore, R. , Dr. University of New Hampshire

Bretz, M. , Dr. University of Maryland

Carroll , D . F . , Dr

.

The Pennsylvania State University

Cava , R . , Dr

.

AT&T Bell Labs

Chan, H.M., Dr. Lehigh University

Chen , C . F . , Mr

.

University of Michigan

Chen, Sharon, Ms. Duke University

Cho , Seong-Jai Korea Standards Research Institute

Craig , C . H . , Mr

.

Department of Defense

Darnall , D . , Dr

.

New Mexico State University

Davies , P . , Dr

.

University of Pennsylvania

Davis, K. University of Maryland

Deckman, Douglas E. The Pennsylvania State University

Degnan , T . , Dr

.

Mobil Oil Company

Deshmukh , U . , Dr

.

Drexel University

Dong, Jie-Yi East China University of Chem. and Tech.

Dong, Xiaoyuan Tsinghua University

Eng , G . , Prof

.

University of the District of Columbia

Gates, Richard S. The Pennsylvania State University

Gilat , A . , Mr

.

Israel Ministry of Defense

Guard, H. E. , Dr. Office of Naval Research

57
Guenther , K . , Dr

.

University of Alabama

Haller, Wolfgang, Dr. National Bureau of Standards

Inglehart, L. , Dr. Johns Hopkins University

Kelly, R. , Dr. Johns Hopkins University

King, R. , Dr. Department of Energy

Kuchinski , M. Rutgers University

Laor, Uri Dr. Nuclear Research Center, Israel

Lathabai, S. Lehigh University

Legal LeSalle, E., Mr. ESPCI , France

Lim, Dae-Soon University of Illinois

Matthias , C . , Ms

.

University of Maryland

McMurdie, H. The American Ceramic Society

Miller, P. J . , Mr. Naval Surface Weapons Center

Mizuhara, Kazuyuki Japan Ministry of International Trade/Industry

Mysen, J . , Dr

.

Carnegie Institute

Neifeld, R. , Dr

.

Harry Diamond Labs

Nguyen, Christie, Ms. University of Pennsylvania

Palamides , T . , Mr

.

Drexel University

Parker, H. National Bureau of Standards

Ritter , A . P . , Mr

.

Martin Marietta Laboratory

Rosenblatt, D., Mr. University of Pennsylvania

Sakai , C . , Mr

.

University of Maryland

Su, W. , Mr. Johns Hopkins University

Sun, Y. , Mr. Lanzhou Institute of Physics

Swanson, Peter L. , Dr. University of Colorado

Tewary, V.K., Prof. Ohio State University

Thayer , J . , Dr

.

University of Cincinnati

58
Tierney , E . , Ms

.

University of Maryland

Trout , T . , Mr

.

University of Maryland

Vandiver , P . B . , Dr

.

Smithsonian Labs

Wang, Fu-Xing Tsinghua University

Wang , Yusha Tsinghua University

Whitler, J. University of Maryland

Wilson, Annie, Ms. Oberlin University

Winzer , S . R . , Dr

.

Martin Marietta Laboratory

Wong-Ng . , W . , Dr

.

University of Maryland

Yeheskel, Ori , Dr. Nuclear Research Center, Israel

Yellets, Jeffrey P. The Pennsylvania State University

Ying, Tsi-Ning Tsinghua University

Ying, X. , Mr. Fudan University, Shanghai, Peoples Republic of

China

Zelibor , J . , Dr

.

University of Maryland

Zheng, Pei-Yi RIPP

9
'

'
OUTPUTS AND INTERACTIONS

Ceramic Powder Characterization

Dragoo, A. L. ; Hsu, S. M. Ceramic powder characterization - future needs.

Proceedings of the International Workshop for Advanced Material Technology

- Ceramics II, Nagoya, Japan, March 1987; to be published,

Wong-Ng, W. ; Cook, L. P. X-ray studies of helium-quenched Ba2 YCu3 07 _ x

. Adv

Ceram. Mater. 2 ( 3 B ) : 624-31; 1987.

Wong-Ng, W. ; McMurdie , H. F. ; Paretzkin, B.; Zhang, Y. ; Davies, K. L.

;

Hubbard, C. R. ; Dragoo, A. L. ; Stewart, J. M. Standard x-ray diffraction

powder patterns of sixteen ceramic phases. Powder Diffraction. 2(2); 106-

117; 1987.

Wong-Ng, W. ; Roth, R. S. X-ray characterization of 2BaO:CuO. J. Am. Ceram.

Soc. Commun. in press.

Processing Science Group

Blendell, J.E.; Chiang, C.K.; Cranmer, D.C.; Freiman, S.W.; Fuller, E.R.

Jr.; Drescher-Krasicka , E.; Johnson, W.L.; Ledbetter, H.M.; Bennett, L.H.;

Swartzendruber , L.J.; Marinenko, R.B.; Myklebust, R.L.; Bright, D.S.;

Newbury, D.E. Processing-property relations for Ba2 YCu3 07

_ x high Tc superconductors. Adv. Ceram. Mat. 2(3B): 512-529; 1987.

Chiang, C.K.; Cook, L.P.; Chang, S.S.; Blendell, J.E.; Roth, R.S. Low

temperature thermal processing of Ba2 YCu3 07

_ x superconducting ceramics.

Adv. Ceram. Mat. 2(3B): 530-538; 1987.

Coyle, T.W.; Ingel, R.P.; Willging, P.A. The temperature dependence of

fracture toughness and yield strength in unstabilized zirconia crystals.

Advanced Structural Ceramics . MRS Symposia Proceedings Series, 7.8: edited

by P. F. Becher, M. V. Swain, and S. Somiya, Materials Research Society,

Pittsburgh, PA; 89-86; 1987.

Coyle, T.W.; Palamides, T.R.; Freiman, S.W.; Fuller, E.R. Jr., Deshmukh, U

Crack-fiber interactions in ceramic matrix composites. Proceedings of

Conference on "High Temperature Structural Composites: Synthesis,

Characterization and Properties", The Metallurgical Society 1987 Regional

Meeting, 1987, in press.

da Jornada, J.A.H.; Piermarini , G.J.; Block, S. Metastable retention of a high pressure phase of zirconia. J. Am. Ceram. Soc. 70: 1987.

Davis, K. ; Roth, R.S.; Piermarini, G.J.; Block, S. Synthesis of and high

pressure phase transition in single crystals of leucite (KAJ?Si 2 06 , and

RbAiSi2 06 , and CsAiSi2 0 6 ). Amer. Mineral., in press.

Ostertag, C.P. Technique for measuring stresses which occur during sinter

ing of a fiber-reinforced ceramic composite. Am. Ceram. Soc., in press.

60
Tewary, V.K.; Fuller, E.R., Jr.; Thomson, R.M. Green function method for

calculation of atomistic structure of grain boundary interfaces in ionic

crystals," in Ceramic Microstructures 86: Role of Interfaces . 1986, in

press

.

Vaudin, M.D.; Handwerker, C.A.; Blendell, J.E. Electron microscopy studies

of diffusion- induced grain-boundary migration in ceramics. J. de Physique,

in press

.

Ceramics Chemistry and Bioprocesses Group

Bellama, J. M.; Jewett, K. L. ; Nies, J. D. Rates of methylation of mercury

II species in water by organotin and organo silicon compounds.

Environmental inorganic chemistry, A. F. Martell and K. J. Irgolic, eds .

,

in press.

Manders , W. F.; Bellama, J. M. ; Johannesen, R. B,; Parks, E. J.; Brinckman,

F. E. Characterization of organometallic polymers by 13 C and 119 Sn NMR

configurational/compositional triads in poly ( tri-n-butyltin

methacrylate/methyl metacrylate) . J. Poly. Sci,; in press.

Olson, G. J.; Brinckman, F. E. Microbial metal leaching and resource recovery processes. In: Frontiers in bioprocessing, S. K. Sikdar, ed.

,

CRC Press, Inc., Boca Raton, FL. ; in press.

Olson, G. J.; Kelly, R. M. Microbiological processing of coal. In:

Bioprocessing of fossil fuels, D. Wise, ed. , CRC Press, Boca Raton, FL. ; in

press

.

Parks, E. J.; Kool, L. B.; Brinckman, F. E. Characterization of organolead

polymers in trace amounts by element-specific size exclusion

chromatography. J. Chromatogr.; 370: 206-209; 1986.

Ritter, J. J.; Frase, K. A. Low temperature synthesis of ceramic powders

for structural and electronic applications. In: Science of Ceramic

Chemical Processing, L. L. Hench, D. R. Ulrich, eds., J. Wiley & Sons, New

York; 497; 1986.

Ritter, J. J.; Roth, R. S.; Blendell, J. E. Alkoxide precursor synthesis

and characte ization of phases in the barium- titanium oxide system. J.

Amer. Cer. Soc . ; 69: 155; 1986.

Roth, R. S.; Ritter, J. J.; Parker, H. S.; Minor, D. B. Synthesis,

stability and crystal chemistry of dibarium pentatitanate . J. Amer. Cer.

Soc. ; 69: 858; 1986.

Yeh, T. Y. ; Godshalk, J. R. ; Kelly, R. M. ; Olson, G. J. Use of

epif luorescence microscopy for characterizing the activity of Thiobacillus

f errooxidans on metal sulfides. Biotechnol. Bioengin. ; in press.

61
High Temperature Chemistry

Bonne 11 , D. W. ; Hastie, J. W. ; and Zmbov, K. F. Transpiration mass spectrometry of liquid LiF -- vaporization thermochemistry and electron

impact fragmentation. High Temp. High Press; in press 1987.

Cook, L. P.; Bonnell, D. W. ; Hastie, J. W. Model for molten salt corrosion

of (Co , Cr) -based superalloys NBSIR 87-3628 1987.

Cook, L. P.; Chiang, C. K. ; Wong-Ng W. ; Blendell, J. Thermal analysis of

Ba2 YCu3 0 at 700-1000°C in air: Adv. Ceramic Materials 2(3B): 656-661;

1987. /_X

Davidson, P. M. Phase separation in quadrilateral pyroxenes and olivines.

Advances in Physical Geochemistry, S. Ghose , ed.; in press, 1987.

Davidson, P. M. ; Burton, B. P. Order-disorder in omphacitic pryoxenes : A. model for coupled substitutions in the point approximation. American

Mineralogist, 72 : 337-344; 1987.

Hastie, J. W.; Bonnell, D. W. ; Schenck, P. K. Thermochemistry of materials

by laser vaporization mass spectrometry, Part II. graphite.

High Temp. High Press; in press (1987). See also NBSIR - 873561.

Hastie, J. W. ; Bonnell, D. W. ; Schenck, P. K. Laser induced vaporization

mass spectrometry of refractory materials. Part I. Apparatus and the BN

system. High Temp. Science; in press 1987.

Schenck, P. K. ; Dennis, J.R. Graphics program for binary and ternary

ceramic phase diagrams. In Proc . Users Conference on "User Applications of

Alloy Phase Diagrams", Oct. 1986 Orlando, FL (Ed. L. Kauffman)

Schneider, S. J.; Hastie, J. W.; Holbrook, W. D. Phase diagrams for high

tech, ceramics. In Elsevier pub. Proceedings of World Congress on High

Tech. Ceramics, Milan, June (1986); in press 1987.

Synchrotron Radiation Group

Bennett, L. H.; Long, G. G.; Kuriyama, M. ; Goldman, A. I. Local atomic structure in transition metal/metaloid glasses: Ni-Pin

structure and bonding in noncrystalline solids. ed. by G . E. Walrafen and

A. K. Revez., Plenum, NY 385-409; 1986.

Kennedy, J. J.; Amirtharaj , P.M.; Boyd, P.R.; Qadri, S.B.; Dobbyn, R. C.;

Long, G. G. Growth and characterization of CdZnTe and HgZnTe . J. Cryst.

Growth, in press.

Kuriyama, M. ; Dobbyn, R. C.; Takagi , S.; Chow, L. C. Microradiography with

an x-ray image magnifier. (translated in Japanese) (Invited article)

S E I BUT SU - BUT SUR I (Biophysics) 27: 1987.

62
Kuriyama, M.; Dobbyn, R. C.; Takagi , S.; Chow, L. C. Microradiography with

an x-ray image magnifier: application to dental hard tissue. Medical

Physics, in press.

Pella, P. A.; Dobbyn, R. C. Monochromatic synchrotron x-radiation for the

EDXRF analysis of selenium in serum using total reflection geometry.

Analytical Chemistry, in press.

Pella, P. A.; Dobbyn, R. C. Total reflection XRF analysis with

monochromatic synchrotron radiation: advances in x-ray analysis. 31 : Plenum, NY, in press.

Robbyn, R. C.; Kuriyama, M. ; Takagi, S.; Chow, L. C. High resolution

radiography: applications to biomedical imaging in biomedical engineering

VI: recent development. eds . R. C. Eberhart and L. Howard

McGregor and Werner Pub., in press.

Steiner, B,; Laor, U.; Kuriyama, M. ; Long, G.G.; Dobbyn, R. C. Diffraction

imaging of high quality bismuth silicon oxide with monochromatic

synchrotron radiation: Implications for Crystal Growth. J. Crystal Growth,

in press

.

Glass and Composites

Baker, T. C.; Freiman, S. W. Fracture behavior of ceramics use in

multilayer ceramics. Electronic Packaging Materials Science II, Materials

Research Society, 72 : 81; 1986.

Blendell, J. E. et al . Processing-property relations for Ba2 YCu5 07

_ x high

Tc superconductors. Advanced Ceramic Materials 2.(3B): 530; 1987.

Chiang, C. K. et al. Low temperature thermal processing of Ba2 YCu3 07 _ x AcerS superconducting ceramics. Advanced Ceramic Materials 2(3B): 530;

1987.

Freiman, S. W. Mechanical behavior of ferroelectric ceramics. Proceedings

of the 6th IEEE Int. Symp . on Appl. of Ferroe lectrics 367; 1986.

Freiman, S. W.; Michalske, T. A.; Bunker, B. C. Stress corrosion of ionic

and mixed ionic/covalent solids. J. Am. Ceram. Soc . 69.: 721; 1986.

White, G. S.; Freiman, S. W. ; Wiederhorn, S.M.; Coyle, T. D. Effects of

counter ions on crack growth in vitreous silica. To be published in J. Am.

Ceram. Soc.

White, G. S.; Fuller, E. R., Jr.; Thomson, R. M. Environmentally enhanced

crack growth in glass modeled by Greens function. Proc . of the TMS-AIME

Fall Meeting, 1986.

63
Mechanical Properties Group

Chuang, T.-J.; Wiederhorn, S.M.; Chen, C.F. Transient behavior of

structural ceramics under flexural creep. Creep and Fracture of Eng;.

Mater, and Struct. Ed. by B. Wilshire and R.W. Evans, Institute of Metals

957-973; 1987.

Clarke, D.B.; Lawn, B.R.; Roach, D.H. The role of surface forces in

fracture. Fracture Mechanics of Ceramics . R.C. Bradt , A.G. Evans, D.P.H.

Hasselman and F.F. Lange, eds., Plenum, New York (8): 341; 1986.

Swanson, P/L.

;

Fairbanks, C.J.; Lawn, B.R.; Mai, Y.-W.; Hockey, B.J.

Crack- interface grain bridging as a fracture resistance mechanism in

ceramics: I. experimental study on alumina. J. Am Ceram. Soc. (70): 279;

1987.

Wiederhorn, S.M; Fuller, E.R. Jr. Design criteria for high temperature

structural applications. Ceramic Materials and Components for Engines,

W. Bunk and H. Hausner, eds. Deutsche Keramische Gesellschaft e.v., D5340, Bad Honnef; 911-929; 1986.

Wiederhorn, S.M.; Chuck, L. ; Chuang, T.-J.; Jakus, K. Standard tensile

test development. Proceedings of the 24th Automotive Technology

Development Contractors Coordinating Meeting, October 29, 1986, Soc.

Automotive Engineers, Warrendale, PA; 1987.

Tribology Group

Gates, R.S.; Yellets, J.P.; Deckman, D.E.; Hsu, S.M. Considerations in

ceramic friction and wear measurements, presented at the ASTM meeting in

Cincinnati, OH, May 1987 (to be published as ASTM SP)

.

Hsu, S.M.; Ku, C.S.; Pei, P.T. Oxidative degradation mechanisms of

lubricants, ASTM SP 916, 27; 1986.

Neihof, R.A. ; Ross, M.M.

;

Munro , R.G.; Hsu, L.S.; Ku, C.S. High

temperature lubricants from biodeuterated materials produced by algae, div

of petroleum symposium preprints, ACS, (32., 865; 1987.

Pei, P.; Hsu, S.M. Preparative liquid chromatographies method for

the characterization of minor constituents of lubricating base oils.

J. Chrom. 9 (15): 3311-3345; 1986.

Weeks, S.; Lawson, R. ; Pei, P.T.; Hsu, S.M. Chemiluminescence

instrumentation for fuel and lubricant oxidation studies. To be published

in STLE Trans .

Optical Materials Group

Farabaugh, E. N. ; Sun, Y. N. ; Sun, J. ; Feldman, A; Chen, H. H. A study of

thin film growth in the Zr02 -Si02 system. Laser Induced Damage in Optical

Materials (1986), Boulder, CO; in press.

64
Feldman, A.; Sun, Y. N.; and Farabaugh, E. N. Bonding structure of silicon

oxide films; in press.

Feldman, A.; Fuller, E.; Bendow; B,; Levin, K. Photoelastic characteristic of f luorozirconate and transition-metal fluoride glasses.

Proceedings of the 4th International Symposium on Halide Glasses, Monterey,

CA, 1987; in press.

Frederikse, H,; Feldman, A. Thermal wave inspection of heat resistant

ceramic coatings. Proceedings of Conf. on Non-Destructive Testing of High

Performance Ceramics, Boston, MA, 1987; in press.

Sun, Y. N.; Feldman, A.; Farabaugh, E. N. X-Ray photoelectron spectroscopy

of 0 Is and Si 2p lines in films of SiOx formed by e-beam evaporation; in

press

.

Computerized Data Activities Group

Beech, F. ; Miraglia, S.; Santoro, A.; Roth, R.S. Neutron study of the

crystal structure and vacancy distribution in the superconductor

Ba2 YCu3 09

_ x

. Phys. Rev. B, 35(16): 8778-8781; 1987.

Ondik, H.M; Messina, C.G. Creating a materials database builder and

producing publications for ceramic phase diagrams. ASTM Special

Publication, Proceedings of the 1 st International Symposium on Computerized

Materials Property Data, Nov. 1987, in press.

Roth, R.S.; Davis, K.L.; Dennis, J.R. Phase equilibria and crystal

chemistry in the system Ba-Y-Cu-O. Advanced Ceramic Materials, 2(3B):

Special Supplementary Issue, 303-312; 1987.

Roth, R.S.; Dennis, J.R.; McMurdie , H.F. Phase Diagrams for Ceramists,

Volume 6, editors, American Ceramic Society, 1987, in press.

Roth, R.S.; Ettlinger, L.D.; Parker, H.S. Phase equilibria and crystal

chemistry in the ternary system Ba0-Ti02 -Nb2 05

. J. of Solid State Chem.,

68: . 330-339; 1987.

Schenck, P.; Dennis, J. PC-access to ceramic phase diagrams. ASTM Special

Publication, Proceedings of the 1 st International Symposium on Computerized

Materials Property Data, Nov. 1987, in press.

Wong-Ng, W. ; Roth, R.S.; Swartzendruber , L.J.; Bennett, L.H.; Chiang, C.K.;

Beech, F. ; Hubbard, C.R. X-ray powder characterization of Ba2 YCu3 07 _ x

. Advanced Ceramic Materials, 2(3B): Special Supplementary Issue, 565-576;

1987.

65
SELECTED TECHNICAL/PROFESSIONAL COMMITTEE LEADERSHIP

American Ceramic Society

Glass Division

S. W. Freiman

Committee on Glass Standards Classification and

Nomenclature

M. J. Cellarosi, Chairman

Editorial Committee

S. Wiederhorn, Subchairman

Basic Science Division

Editorial Committee

B. R. Lawn, Chairman

Program Committee

E. R. Fuller, Jr., Chairman

Communication of the American Ceramic Society

E. R. Fuller, Jr., Contributing Editor

American National Standards Institute (ANSI)

Committee 43.1- -Safety Standards for x-ray Diffraction and

Fluorescence Analysis Equipment

S. Block, Chairman

American Physical Society Editorial Board

Review of Scientific Instruments

P. K. Schenck

ASM International

Energy Division Fuel Manufacturing Subcommittee

S . J . Dapkunas , Chairman

Journal of Engineering Materials

S. J. Dapkunas, Associate Editor

American Society for Testing and Materials

C14: Glass and Glass Products

M. J. Cellarosi, Chairman

C14.01: Nomenclature of Glass and Glass Products

M. J. Cellarosi, Chairman

FI : Electronics

FI: 02: Laser

A. Feldman, Subcommittee Editor

D2 : Petroleum Products and Lubricants

D2.09G: Oxidation

J. M. Perez, Chairman

C. S. Ku, Secretary

E29.01: Advanced Ceramics, Organizational Meeting

M. J. Cellarosi

E48.03.07: Bioleaching of Ores

G. J. Olson, Task Group Chairman

E49.01.02 Computerization of Materials Property Data

C. R. Hubbard, Chairman

67
American Society of Mechanical Engineers

Research Committee on Tribology

S. Jahanmir, Chairman

Tribology Textbook Editorial Committee

S. Jahanmir, Chairman

COMAT Subcommittee on Structural Ceramics

S. M. Hsu, Member

COMAT Subcommittee on Superconductivity

S . J . Dapkunas , Member

Department of Energy

ECUT - Tribology Program, Guidance and Evaluation Panel

S. Jahanmir, Member

Materials Review Board for Nuclear Waste

H. P. R. Frederikse, Member

Gordon Research Conference on Tribology

S. M. Hsu, Chairman

International Commission for Optics

U. S. National Committee

B. Steiner, Chairman

International Energy Agency

Task II - International Standards

Assignment II-0-2 Powder Characterization Working Group

A. L. Dragoo, Member

Assignment II-0-3 Ceramic Characterization

E. R. Fuller, Jr., Member

International Union of Crystallography (IUCr)

Commission on Crystallographic Studies at Controlled

Pressures and Temperatures

G. J. Piermarini, Chairman

International Union of Pure and Applied Chemistry

Commission 1 1 - 3 : High Temperature and Solid State Chemistry

J. W. Hastie, U.S.A. Associate Member

JCPDS - International Centre for Diffraction Data

C. R. Hubbard, Vice-Chairman

NAS Assessment Committee on Ceramic Tribology

S. M. Hsu, Member

National Academy of Sciences/National Research Council

Solid State Sciences Panel

H. P. R. Frederikse, Member

National Aeronautics and Space Administration

High Temperature Advisory Committee

D. W. Bonne 11, Member

68
National Materials Advisory Board, National Academy of Sciences

Committee on Ceramic Tribology

S. M. Hsu, Member

S. Jahanmir, Member

Oak Ride National Laboratory

High Temperature Materials Laboratory Advisory Committee

S. M. Wiederhorn, Chairman

Society of Automotive Engineers

Task Group on Recommended Practices for the Measurement of

Unregulated Diesel Emissions

J. M. Perez, Chairman

Society of Tribologists and Lubrication Engineers

Annual Meeting Program Committee

S. M. Hsu, Chairman

Board of Directors

S. M. Hsu, Director

Ceramics Activity

S. Jahanmir, Paper Solicitation Chairman

Tribomaterials Committee

S. Jahanmir, Chairman

Wear Technical Committee

S. Jahanmir, Paper Solicitation Chairman

Superconductor Applications Association

E. R. Fuller, Jr., Member of Advisory Board

Versailles Project on Advanced Materials and Standards (VAMAS)

International Round-Robin in Ceramic Working Area

S. W. Freiman, Co-chairman

E. R. Fuller, Jr., Co-chairman

69

INDUSTRIAL AND ACADEMIC INTERACTIONS

The Ceramics Division actively participates with Industry, Academia and

other Government Laboratories in research programs of mutual interest. The

following examples are illustrations .

INDUSTRIAL

1. Cummins Engine Co.

A simple bench test method to evaluate diesel engine oil performance

was developed in cooperation with Cummins Engine Co. Validation of

the method is being performed using samples from Detroit Diesel

Allison Division, GMC and Caterpillar, Inc.

2. John Deere and Company

A joint project between NBS and John Deere and Co. was conducted to

analyze the wear of ceramic engine components. Deposits on the

component surface were analyzed using FTIR spectroscopy, SEM, and gel

permeation chromatography coupled with graphite furnace atomic

absorption spectroscopy.

3. Accumetrix Corporation

H. P. R. Frederikse is collaborating with Dr. David Greenspan of

Accumetrix Corporation to study the thermal and adhesive properties of

plasma sprayed ceramic films. The films are prepared at Accumetrix

and their properties are measured by means of photothermal radiometry.

The research is expected to result in means for monitoring the

production quality of ceramic coatings.

4. BDM Corporation

A. Feldman collaborated with B. Bendow of the BDM Corporation in the

measurement of the piezo-optic coefficients of f luoro-zirconate and

heavy metal flouride glasses. The glasses are being developed for use

as low loss infrared fiber-optic materials.

5. AT&T Bell Laboratories

Dr. R. Cava and Dr. R. Roth of the Ceramics Division have collaborated

on phase equilibria and crystal chemistry in the Ba-Y-Cu-0 system.

6. AVX Corporation

S. W. Freiman, D. C. Cranmer and M. L. Balmer of the Glass and

Composite Group are working closely with Dr. Bharat Rawal of AVX on a program to understand the mechanical properties of multilayer ceramic

capacitors. AVX is preparing specimens of differing composition and

properties T These are subsequently tested at NBS. AVX claims that

development of new materials based on these test results has saved the

71
company a substantial amount of money because of fewer capacitors lost

during processing.

7. VAMAS

The Tribology Group is participating in the international wear test

standardization project. Results of the first round-robin study have

been submitted and recommendations for improved procedures are being

prepared. Dr. Stephen Freiman and Dr. Edwin Fuller are leading a study to develop a test procedure for determining the stress corrosion

susceptibility of ceramics. Approximately 20 laboratories in 6 countries are participating in an interlaboratory test programs.

8. Dupont- Savannah River

Drs . Hastie and Bonnell are collaborating with D. Bickford

(Dupont) on vaporization behavior under processing conditions for

borosilicate nuclear waste glass. Dupont provides samples and

plant data and NBS provides basic data and process mechanisms for use by plant engineers.

9. Inland Steel

Drs. Plante and Bonnell have been collaborating with Dr. H. Pielet of Inland on the thermochemistry of blast furnace and

steel slags and inorganic inclusions in steel. Dr. Pielet

provides slag samples and data from plant experience, Dr. Plante

is providing thermochemical data from high temperature mass spectrometry, while Dr. Bonnell supplies database and model

techniques

.

10. NASA/Cal Tech Jet Propulsion Lab (Pasadena, CA)

Dr. David Bonnell is collaborating and consulting on design of

levitation systems for space applications.

11. Sandia Livermore Combustion Research Facility

John Hastie participated in a review workshop of future planning

for the facility with special responsibility for research needs

at combustion/materials interfaces.

12. IUPAC Commission II -3 on High Temperature and Solid State Materials

Dr. John Hastie, together with the other international members,

planned the 5th conference on High Temperature and Energy-Related

Materials held in Rome (May 1987) . The Sixth conference is

scheduled to be held at NBS (1989) and will be chaired by John

Hastie

.

72
13. Center for the Development of Commercial Crystal Growth in Space at

Clarkson University

The Synchrotron Radiation Group is a member of the Center and is

Conducting collaboration research on the structure of materials as a function of growth parameters

.

14. Advanced Composite Materials Corporation

E.R. Fuller, Jr. and R.F. Krause, Jr. of the Processing Science Group

are interacting with Dr. James F. Rhodes of ACM on microstructural and

structural characterization of silicon carbide whisker- reinforced

alumina composites, correlating mechanical properties to microstructural properties and to processing conditions.

15. Raytheon Company

S. Block and G.J. Piermarini of the Processing Science Group are interacting with Dr. R, Gentilman of Raytheon and Dr. P.E.D. Morgan of

Rockwell International Science Center on a U.S. Navy program to

develop tougher, infrared- transmitting missile windows through the

evaluation of test samples for potential transformation toughening

agents

.

16. Stauffer Chemical Company

J.E. Blendell, E.R. Fuller, Jr., and L.C. Stearns of the Processing

Science Group are interacting with Dr. F.A. Via of Stauffer Chemical

on the sintering of YBa2 Cu3 07 _ x ceramic superconductors formed from

chemical precursor routes.

17. Max Planck Institut, Stuttgart, Federal Republic of Germany

J.E. Blendell and M.D. Vaudin of the Processing Science Group and

C.A. Handwerker of the Metallurgy Division have collaborated with

Dr. Wolfgang Kaysser of MPI on the sintering of ceramics and on diffusion induced, grain-boundary migration in ceramics and metals.

18. Naval Research Laboratory

Cooperative research between Dr. R.P. Ingel of the Naval Research

Laboratory and T.W. Coyle of the Processing Science Group is performed

concerning studies of phase transformations and toughening mechanisms

in Zr02 containing ceramics

.

19. Oak Ridge National Laboratory

T. W. Coyle, E.R. Fuller, Jr. and R.F. Krause, Jr. of the Processing

Science Group are interacting with Drs . T.M. Besmann, D.P. Stinton,

A.J. Caputo , and R. Lowden of ORNL on the microstructural and

structural characterization of ceramic matrix composites produced by

chemical vapor inf ilitration , correlating mechanical properties to

microstructural properties and to processing conditions.

73
20. American Iron and Steel Intitute

G. J. Olson of the Surface Chemistry and Bioprocesses Group is a member of the AISI - Federal Laboratory Task A subcommittee on scrap

recycling. The Group is also examining upgrading of ores and

concentrates via biological removal of phosphorus, silicon, and

sulfur

.

21 . Electric Power Research Institute

EPRI is funding a joint project between members of the Ceramic

Chemistry and Bioprocesses Group and The Johns Hopkins University

investigating microbio - logical bioasays to determine coal sulfur

speciation and biodesulfurization of coal by extremely thermophilic

bacteria

.

22. Idaho Mining Association

F. E. Brinckman and G. J. Olson of the Ceramics Chemistry and

Bioprocesses Group are working with members of the IMA and the Idaho

National Engineering Laboratory to develop novel processes for

extraction and separation of precious metals.

23. St. Joe Minerals

Members of the Ceramics Chemistry and Bioprocesses Group are investigating the bioleaching of St. Joe smelter wastes high in

strategic metal content as a possible means for cost-effective

recovery

.

24. Technical Research Associates, Inc. and the U.S. Air Force

G. J. Olson of the Ceramics Chemistry and Bioprocesses Group is

consulting with TRA, Inc. and the U.S. Air Force to develop novel

microbial processes for leaching and recovery of gallium from domestic sources

.

25. Cleveland Cliffs Iron Co. and Michigan Tech

Promising data obtained under the Steel Research Program by members of

the Ceramics Chemistry and Bioprocesses Group have encouraged CCI and

Michigan Tech to propose to the State of Michigan the development of an industrial process for biological removal of phosphorus from iron

ores. NBS would be a consulting collaborator in the project.

74
JOINT INDUSTRIES /UNIVERSITIES

1. Detroit Diesel Allison Division, General Motors and Pennsylvania State

University

High temperature vapor phase lubrication studies in progress at the

Pennsylvania State University funded under our program have resulted

in cooperative studies between Penn State and Detroit Diesel Allison

Division, GMC . The technology will be used in low heat rejection

engine research studies at DDAD

.

2. Gas Research Institute and Penn State University

The Division is participating with GRI and PSU on research addressing

the mechanical and tribological properties of materials for gas fired

applications

.

UNIVERSITIES

1. University of Michigan

Joint research with Professor T.Y. Tien on the creep and creep rupture

behavior of SiAiON composites at high temperature. These materials

were manufactured at the University of Michigan and characterized both

microstructurally and mechanically at NBS by C.F. Chen a graduate

student from the University of Michigan. This work was conducted in

collaboration with T.-J. Chuang, and S.M. Wiederhorn of the Mechanical

Properties Group.

2. Lehigh University

Joint research with Professor Martin P. Harmer on the effect of

microstructure on the fracture resistance of ceramic materials. The

materials under study will be manufactured at Lehigh University and

will be characterized and tested at the National Bureau of Standards

by Dr. S. J. Bennison a Guest Scientist from Lehigh University. This

work is being conducted in collaboration with Dr. B. R. Lawn of the

National Bureau of Standards.

3. Northwestern University

Joint research involves lubrication modeling between NBS and Prof.

Herbert Cheng. The research focuses on the microelastohydrodynamic

theories under wearing conditions. This is the first attempt at

combining surface chemistry with surface mechanics to create a predictive wear model. Tim Ovaert of the Northwestern University has

participated in the development of high temperature wear testing

facility

.

4. Pennsylvania State University

The Tribology Group has several joint research projects with the

Department of Chemical Engineering and the materials Research

Laboratory at PSU. The research projects include fundamental studies

75
on the vapor phase lubrication of ceramic materials at high

temperature; microstructural effects in ceramic wear processes; high

temperature friction and wear tribometer design; and ceramic wear

modeling which seeks to establish a theoretical understanding of

ceramic wear processes.

5. University of Illinois

Steven Danyluk and Dae -Soon Lim of the Department of Civil

Engineering, Mechanics, and Metallurgy are conducting joint research

with NBS . The project centers on an investigation of the fundamental

mechanisms of friction, wear, and surface damage in tribological

applications of advanced ceramics.

6. University of Maryland

S. Jahanmir of the Tribology Group is Adjunct Professor in the

Department of Mechanical Engineering. He participates in joint

research activities between NBS and the University of Maryland.

7. Tsinghua University

J. Dong, X. Dong, F. Wang, Y. Wang and T. Ying of Tsinghua University

are conducting tribology research at NBS. This joint research

activity is concerned with the mechanisms of wear and lubrication of

ceramics

.

8. North Carolina State University

A. Feldman and E. N. Farabaugh collaborated with R. Nemanich of North

Carolina State University in measuring the Raman spectrum of a diamond

film deposited at NBS.

9. University of Pennsylvania

Prof. P. Davies and Dr. R. Roth are collaborating on the properties

and structure of microwave dielectrics and high Tc superconductors.

10. North Carolina State University

Dr. R. Porter and J. Dennis of the Ceramics Division are collaborating

on wetting during melt formation of the 1:2:3 superconductor phase.

11. Penn State University

Dr. John Hastie participated in the Ceramics Department graduate

seminar program and Drs . John Hastie and Ernest Plante of NBS and

Prof. C. Pantano (Penn State) are collaborating on studies of

vaporization mechanisms of Ge-Se-Sb glass systems.

76
12. The Johns Hopkins University

Robert Kelly of the Chemical Engineering Department and G. J. Olson

and F. E. Brinckman are conducting joint research on microbial

processing of coal. Olson is guest lecturer in Chemical Engineering

Department. Another project on characterizing microbial activity on mineral surfaces is being conducted with JHU and Martek Corp.,

Columbia, MD.

13. University of Cincinnati

Scientific collaboration with Professor John S. Thayer on molecular

mechanisms of metal solubilization and transformation by biogenic

metabolites is being pursued.

14. University of Maryland

Members of the Ceramics Chemistry and Bioprocesses Group are collaborating with Professor Michael Bellama and his doctoral students

on biological and chemical transformations of organometallic materials

in environmental situations. Brinkman is adjunct professor in the

Chemistry Department.

15. University of New Hampshire

The Surface Chemistry and Bioprocesses Group is collaborating with

Professor Richard H. Blakemore on in vivo characterization of metal

particle formation rates and sites in magnetite-depositing bacteria,

using SANS characterization. G. J. Olson, F. E. Brinckman and K. Rhyne are participating in the research.

16. University of Siena, Italy

G. J. Olson and F. E. Brinckman are collaborating with Dr. Franco

Baldi on microbiological leaching of metal ores.

17. University of the District of Columbia

F. E, Brinckman is collaborating with Professor George Eng on molecular properties of organometallic compounds.

18. Georgia Tech Research Institute

T.W. Coyle and E.R. Fuller, Jr. of the Processing Science Group are interacting with Dr. Thomas Starr of GTRI on the microstructural and

structural characterization of ceramic matrix composites correlating

mechanical properties to microstructural properties and to processing

conditions

.

77
19. Federal University of the Rio Grande of the South (UFRGS)

Porto Alegre, Brazil

G.J. Piermarini of the Processing Science Group has initiated a collaborative research program with Prof. J. A. H. da Jornada at the

UFRGS University on densification and sintering of ceramic materials

using presses to achieve large-scale sample volumes for improved

product testing and evaluation.

20. Harvard University, Division of Applied Sciences

S. Block and G.J. Piermarini of the Processing Science Group have

consultated with Drs . M. Aziz and E. Nygren of Harvard University on setting up a high pressure lab with diamond anvil pressure cells for

low- temperature use.

21. Howard University, Chemistry Department

S. Block and G.J. Piermarini of the Processing Science Group have

collaborated with Prof. G. Walrafen of Howard University on the study

of pressure effects on the structure of liquid and solid phases of

water

.

22. University of Bayreuth, Federal Republic of Germany

G. J. Piermarini of the Processing Science Group has consulted with Dr.

H. Olijnyk of the Research Institute for Experimental Geochemistry and

Goephysics, University of Bayreuth on establishing a high-pressure

laboratory for X-ray diffraction and optical spectroscopy studies at

ultra-high pressures with diamond anvil cells.

23. Drexel University

The Glass and Composite Group is conducting a joint program with Dr.

M. J. Koezak of Drexel University on the fracture behavior of ceramic

matrix composites.

78
STANDARD REFERENCE MATERIALS

The Division provided science, industries, and government a central

source of well-characterized materials certified for chemical composition

of physical or chemical properties. These materials are issued with a certificate and are used to calibrate instruments, to evaluate analytical

methods, or to produce scientific data which can be referred to a common

base

.

SRM

DESCRIPTION NUMBER

Alumina Elasticity 718

Alumina Glass Anneal Point 714

Alumina Glass Anneal Point 715

Alumina Melting Point 742

Aluminum Magnetic Susceptibility 763-1

Aluminum Magnetic Susceptibility 763-2

Aluminum Magnetic Susceptibility 763-3

Barium Glass Anneal Point 713

Borosilicate Glass Composition 93(A)

Borosilicate Glass Thermal Expansion 731L1

Borosilicate Glass Thermal Expansion 731L2

Borosilicate Glass Thermal Expansion 731L3

Cadmium Vapor Pressure 746

Chlorine in Base Oil 1818

Container Glass Composition 621

Container Glass Leaching 622

Container Glass Leaching 623

Copper Thermal Expansion 736L1

Fused Silica Thermal Expansion 739L1

Fused Silica Thermal Expansion 739L2

Fused Silica Thermal Expansion 739L3

Glass Dielectric Constant 774

Glass Electrical Resist 624

Glass Fluorescence Source 477

Glass Liquidus Temperature 773

Glass Refractive Index 1820

Glass Sand (High Iron) 81A

Glass Sand (Low Iron) 165A

Glass Stress Optical Coefficient 708

Glass Stress Optical Coefficient 709

Gold Vapor Pressure 745

High Boron Glass Viscosity 717

Intensity XRD Set 674

Lead Barium Glass Composition 89

Lead Glass Anneal Point 712

Lead Glass Viscosity 711

Liquids Refractive Index 1823

Low Boron Glass Composition 92

Lube Oil Oxidation Test Kit 1817

79
Lube Oxidation Catalysts 8500

Lubricant Oxidation Research Test Kit 8500a

MNF2 Magnetic Susceptibility 766-1

Mica X-Ray Diffraction 675

Neutral Glass Anneal Point 716

Nickel Magnetic Susceptibility 772

Opal Glass Composition 91

Palladium Magnetic Susceptibility 765-1

Palladium Magnetic Susceptibility 765-2

Palladium Magnetic Susceptibility 765-3

Platinum Magnetic Susceptibility 764-1

Platinum Magnetic Susceptibility 764-2

Platinum Magnetic Susceptibility 764-3

Refractive Index Glass 1822

Respirable Quartz 1878

Ruby EPR Absorption 2601

Sapphire Thermal Expansion 732

Silicon X-Ray Diffraction 640(b)

Silver Vapor Pressure 748

Soda Lime Flat Glass Composition S620

Soda Lime Float Composition 1830

Soda Lime Glass Viscosity 710

Soda Lime Sheet Composition 1831

Sulfur in Base Oil 1819

Toluene 5 ML . 211C

Tungsten Thermal Expansion 737

80
APPENDIX
.
CERAMICS DIVISION ORGANIZATION

Division Office Telephone Number: 301-975-6119

Division Chief: Stephen M. Hsu

Deputy Chief: S. J. Dapkunas

Administrative Officer: Sonja C. Lightbody

PROCESSING

Ceramic Powder Characterization

Alan Dragoo, 975-5785

Processing Science

Edwin Fuller, 975-5797

Ceramic Chemistry and Bioprocesses

Frederick Brinckman, 975-5737

STRUCTURE/STABILITY

High Temperature Chemistry

John Hastie, 975-5754

Synchrotron Radiation

Masao Kuriyama, 975-5974

Glass and Composites

Stephen Freiman, 975-5761

PROPERTIES AND PERFORMANCE

Mechanical Properties

Sheldon Wiederhorn, 975-5772

Tribology

Said Jahanmir, 975-3671

Optical Materials

Albert Feldman, 975-5740

Computerized Data Activities

Camden Hubbard, 975-6121
'

.
U

S.

DEPARTMENT

OF

COMMERCE

National

Bureau

of

Standards

FORM NBS-1 14A (REV 11-84)

1. PUBLICATION OR

REPORT NO.

2. Performing Organ. Report No. 3. Publication Date

87-3612 November 1987

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET (See instructions)

4.

TITLE AND SUBTITLE

5. Ceramics Division - Technical Activities 1987

AUTHOR(S)

6.

PERFORMING ORGANIZATION (If joint or other than NBS. see in struction s)

NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

7. Contract/Grant No.

8. Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

NBS - Ceramics Division 420

Building 223, Room A257

Gaithersburg, MD 20899

10.

SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FlPS Software Summary, is attached.

11.

A BSTRACT (A 200- word or less factual summary o f most significant information. If document includes a si gn i fi cant

bi bl i o graph y or literature survey, mention it here)

Current programs of the Ceramics Division are reviewed,

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semi colon sj Composites; glass; mechanical properties; optical materials; powder characterization:

superconductivity; thermodynamics; tribology

13. availability

U n 1 1 mi ted For Official Distribution, Do Not Release to NTIS _ Order From Superintendent of Documents, U.S. Government Printing Office, Washington, DC

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