REFERENCE

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PUBLICATIONS IhSE : -

NAT L INST. OF STAND & TECH R.I.C.

A111QM Saib2M

Institute for Materials Science and Engineering

CERAMICS

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86-3435

1986

Technical Activities

1986
Cover Illustration: The Ba0-Ti0rNb205 Phase Diagram, determined by Dr. R. Roth,

provides key data, for understanding and processing barium titanate

dielectric ceramics. Further information can be found in the High

Temperature Chemistry section of this report.

Courtesy of Dr. R. Roth, Phase Diagrams for Ceramists Data Center
MBS am RESEARCH

INFORMATION CENTER N'SS'R

CICipo

Institute for Materials Science and Engineering

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CERAMICS

S.M. Hsu, Chief

January 1987

NBSIR 86-3435

U.S. Department of Commerce

National Bureau of Standards
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TABLE OF CONTENTS

Page

INTRODUCTION. . . . . 1

TECHNICAL ACTIVITIES

PROPERTIES/ PERFORMANCE

GROUP

Mechanical Properties

Glass and Composites

Tribology

Optical Materials.

, .Sheldon Wiederhorn. ........ 3

, .Stephen Freiman. ........... 6

, . Ronald Munro ............... 8

..Albert Feldman............. n

STRUCTURE/STABILITY

High Temperature Chemistry .....John Hastie 15

Structural Chemistry. ................ .Stanley Block. 22

Ceramic Powder Characterization. ..... .Alan Dragoo. 26

Surface Chemistry and Bioprocesses. .. .Frederick Brinckman. ...... . 29

PROCESSING

Structural Science

Ceramic Chemistry

..Edwin Fuller 35

, .Kay Hardman-Rhyne 39

RESEARCH STAFF

OUTPUTS AND INTERACTIONS

Selected Recent Publications

Selected Technical/Professional Committee Leadership 61

Industrial and Academic Interactions.

Standard Reference Materials

APPENDIX

Ceramics Division Organization Chart

Organizational Chart

National Bureau of Standards

Organizational Chart

Institute for Materials Science 4 Engineering
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INTRODUCTION

Introduction

The Ceramics Division was formally named in 1985 to reflect the increasing

NBS emphasis on the science and technology base associated with advanced

ceramics. The Division conducts research in many aspects of inorganic

materials science and engineering. The primary technical focus of the

Division is to develop 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.

As a result of the successful 1986 budget initiative in ceramics, the

division has undergone considerable expansion in terms of personnel and

research facilities. An extensive recruitment effort has resulted in the

addition of 6 permanent staff, 14 post-doctoral research fellows and visiting

professors. The graduate coop program was strengthened with the signing of

agreements with Rutgers, Pennsylvania State, Drexel and, Northwestern

Universities, and the University of Maryland. This brings the total number

of graduate students in the division to nine. The addition of research

personnel has been concentrated in the areas of ceramic processing and

characterization. Considerable resources were also expended on equipment

and facilities upgrading. A level 10 clean room was designed and is expected

to be operational by the spring of 1987. Many new pieces of equipment and

facilities are under construction or being purchased. These include a hot

isostatic press, an automated x-ray diffraction system with high temperature

(3000°C) measurement capability, high temperature friction and wear measuring

apparatus (1500°C), a surface forces measurement Instrument, an ultra-high

mass spectrometer, and a laser Raman surface analyzer. This trend should

continue in the 1987.

Programmatically, the division has been very active in both the domestic and

international arena. Division staff participated heavily in many technical

societies. Internationally, division staff lead the effort in International

Energy Agency (IEA) coordinated multi-national cooperative research on powder

characterization; and the VAMAS international collaboration on mechanical

properties and wear of ceramics. The first NBS/BAM conference on ceramics

was held in April 1986, at Berlin, to exchange technical information.

The Division's data programs received increasing attention and the programs

were consolidated at the end of FY86 forming a new group. The group,

Computerized Data Activities, centralized many emerging data activities with

the ongoing successful activities in x-ray powder patterns and phase diagrams

for ceramists.

Scientifically, there are many accomplishments in FY86. The most noteable

are: the development of a diffuse reflective FTIR technique to determine the

amount of beta phase in silicon nitride powder, the development of a new theory to explain increased fracture toughness with growing crack size; the

1
measurement of internal strains in crystals using synchotron radiation; the

preparation of Ba^SmTiC^y single crystals leading to the discovery of a new dielectric material; formulation and solution of equations for the atomic

structure of grain boundary interfaces in ionic ceramics using Green’s

function; and development of a novel synthesis route for SiC, TiB2 , and 84c from precursors using alkoxide chemistry.

In FY86 , the division addressed the needs of industry aggressively by

visiting many companies and received industrial visitors. Many collaborative research efforts have been Initiated. The division also participated

actively in the establishment of a center for advanced materials at

Pennsylvania State University sponsored by the Gas Research Institute. NBS

will play a key role interacting with the center and its many industrial

members to address some of the critical technical issues.

At the end of FY 86 , we welcome the addition of the Synchrotron Analysis

Group to our division. With the completion of the facilities at the National

Synchrotron Light Source (NSLS) at Brookhaven National Laboratory, we look

forward to the many exciting possibilities in exploring this new, powerful

technique in addressing many materials science issues in advanced ceramics.

Stephen M. Hsu

Chief, Ceramics Division

September 1986
TECHNICAL ACTIVITIES

PROPERTIES/PERFORMANCE
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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 new theory to explain the observed rising fracture toughness of

monophase ceramic materials with growing crack size was developed.

The source of the toughness of ceramic materials is believed to

originate 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. Studies have shown that this mechanism of

toughening is applicable also at high temperature.

o The role of surface forces in subcritical crack growth was explored

for ceramic materials. Surface forces can account for a number of

physical observations including the healing of ceramics when the

external driving forces are removed, the change in slope of crack

velocity curves when the external environments are changed, and the

presence of fatigue limits. These predictions are being investigated

through experimental studies on mica, glass, and sapphire.

o A study of creep in tension has demonstrated the importance of

cavitation to the creep process. Enhancement of the creep rate by

cavitation results in stress distributions that are time dependent

when components are subjected to bending stresses at elevated

temperatures.

o At equal creep strains, the creep rate of vitreous bonded ceramics

appear to be insensitive to the volume fraction of glass in the

material. By contrast the strain to failure is extremely sensitive to

the volume fraction of glass, suggesting the small amounts of glass

can lead to severe embrittlement at elevated temperatures.

Microstructure and Toughness

B.R. Lawn, C.J. Fairbanks, B.J. Hockey, and Y.-W. Mai 1

1 Guest Scientist, University of Sydney

During the past year the effect of contact damage on the strength behavior

of a number of ceramic materials was studied. Specimens containing an indentation flaw at their centers were placed on a test fixture mounted on an inverted optical microscope. Loads applied to the specimens caused the

cracks to grow. This growth was recorded on a video tape recorder so that

3
the qualitative aspects of crack growth could be documented. Crack growth

did not occur in a continuous fashion but in incremental steps. Fracture

was often interrupted at one point only to restart at a second, adjacent

point. These 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 and failure time as a function of

microstructure. The predictions are currently being tested in stress

rupture studies at room temperature. The output of this project is

expected to suggest changes in current methods of tailoring ceramic

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

processing group at Lehigh University is currently underway to explore this

prospect.

Surface Forces

D.H. Roach, B.R. Lawn and S. Lathabai

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 to measure surface forces using

fracture.

High-Temperature Deformation and Fracture

S.M. Wiederhorn, T.-J. Chuang, N.J. Tighe, R.F. Krause, Jr., B.J. Hockey,

L. Chuck, Y. Lu 1

, J. Sun2 and D.E. Roberts

1 Guest Scientist, Shanghai Institute of Testing Technology, Shanghai, China

2 Guest Scientist, Shanghai Institute of Ceramics, Shanghai, China

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

resolved. With this in mind, our program on high-temperature properties of

ceramics has five objectives: (i) the development of new theories that are capable of predicting time-dependent fracture and deformation behavior at

specified loads and temperature; (ii) the development of new experimental

techniques that can produce reliable creep data; (lii) the generation of a

4
data base on commercially available ceramics and refractories; (iv) the

investigation of kinetic processes that result in strength degradation and

delayed failure; and (v) the examination of microstructures that promote

understanding of mechanisms of response to creep and creep rupture.

High temperature fracture studies during the past year concentrated on magnesium chromate refractory, siliconized silicon carbide, and aluminum

oxide. In all of these studies the strength or creep behavior was characterized as a function of temperature, time, and load.

In this project the creep rupture of magnesium chromate refractory has been

quantified to correlate mechanical properties with failure mechanisms.

Stress-rupture of as-received material was characterized as a function of

temperature. Creep curves exhibiting work hardening strain could be fitted

to a power law function of time, in which the exponents and coefficients

were both stress-and temperature-dependent. The strain rate data were

found to fit this empirical expression to better than 5 percent of the

strain rate.

During the past year, the creep and stress-rupture behavior of

siliconized-silicon carbide were characterized in four-point bending and

pure tension as a function of temperature and stress. It was shown that

cavitation nucleates early in the creep process from preexisting grain

boundary defects. With additional deformation, the nucleation and growth

of defects continues, eventually resulting in large cracks that lead to

failure. Cavitation causes an enhancement of the creep rate and an increase in the stress exponent from 4, in the absence of cavitation, to 12

when cavitation occurs. As a consequence of the cavitation, the neutral

strain axis for bending shifts towards the compressive surface of the test

specimen. A method has been developed for locating the position of zero

strain and is being used to collect data that can be compared with

theoretical treatments of multi-axis creep.

The nucleation and growth of cracks at elevated temperatures was studied on commercial grades of vitreous bonded aluminum oxide by flexural loading.

Vitreous bonded aluminum oxide was selected because it contained glass at

the grain boundaries and could be used as a model for structural materials

that are glass bonded. The creep-rate of vitreous bonded alumina oxide

appears to be independent of the amount of glass initially present in the

material, as indicated by the fact that experimentally idential creep rates

were obtained for materials with *25 v/o and 2 8 v/o glass. This finding

suggests a mechanism in which contact between aluminum oxide grains

dominates the creep process. By contrast, the strain to failure ( 2 0.001

for the 8 v/o glass and 2 0.01 for the 25 v/o glass) appears to be sensitive

to the volume fraction of glass. This, combined with data collected by

transmission microscopy, suggests a strong dependence of crack nucleation

and growth on the volume fraction of glass: the less glass the more

sensitive the material is to crack growth. These data have practical

implications with regard to load bearing capability to vitreous bonded

materials
GLASS AMD 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 environmentally enhanced crack

growth in brittle materials, e.g. gallium arsenide, on the effects of

microstructure and chemistry on the fracture of polycrystalline ceramics

such as those used in multilayer capacitors, and 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 A new mechanism of fracture involving interface localized

microfracturing was identified. This mechanism provides an explanation for the magnitude of the fracture toughness of a number

of ceramic materials.

o Rates of crack growth in vitreous silica tested in basic solutions

were shown to be greatly reduced by the addition of 1 mole of

lithium to the solution. This observation has led to new ideas on ways to suppress stress corrosion in ceramics.

o The stress corrosion susceptibility of 94 percent alumina was shown

to be directly related to the chemical composition of and the

crystalline phases in the grain boundaries. This work has led to an improvement in our ability to choose materials having an optimum

resistance to fracture.

o Fluorescent glass microspheres were developed as calibration

standards for immunochemical analysis.

Fracture of Capacitor Materials

S. W. Freiman and T. L. Baker

Work has been performed to determine the effects of composition and

microstructure on the fracture behavior of ceramics used in multilayer

capacitors. Both the fracture toughness and the susceptibility to stress

corrosion were shown to be strongly dependent on the chemistry and grain

size of the particular material and were sensitive to the addition of

minor quantities of constituents added to vary the electrical properties

of the capacitor. An important observation was that the strength of the

material at small flaw sizes could be correlated with its dielectric aging

6
rate. This correlation is interpreted to be due to the fact that both

strength and aging are controlled to a great extent by the magnitude of

the internal stresses in the material.

Microstructure/Crack Interactions

P. L. Swanson 1

^ost Doc

In-si tu optical and scanning electron microscope observations of the

subcritical fracture process have allowed us to evaluate several

micromechanisms previously proposed as being responsible for a host of

macroscopic fracture phenomena in aluminum oxide and glass ceramics. No

evidence of distributed microcracking ahead of the fracture tip, generally

regarded as a primary micromechanism of fracture, was found in any of the

materials. Instead, interface-localized microfracturing was observed to

operate at positions where tractions are transmitted across the nascent

fracture surfaces. Interface tractions are provided by crack-surface

interlocking and ligamentary bridging by ''islands" of intact material left

behind the advancing fracture front. The crack-length-and

crack-opening-displacement-history dependence of this interface

restraining-force provides a reasonable explanation for (1) the relatively

high toughness of these materials (compared to individual constituents),

(2) R-curve behavior (rising resistance to fracture with crack extension),

and (3) the variability and test-geometry dependence of measured

subcritical crack growth parameters.

Thermal Wave NDE

G. S. White, L. Inglehart 1

, and E. LeGal LaSalle2

1'Guest Scientist, Johns Hopkins University, Baltimore, MD.

2Guest Scientist, Ecole Super ieure de Physique et de Chimie Industrielles

,

Paris, France.

Both mirage and photoacoustic thermal wave systems have been constructed

and are operating. Thermal wave signals obtained on alumina specimens

varying in porosity from 2 to 40 percent exhibited significant

differences. Recently developed models are being applied in order to

separate porosity effects from those due to surface roughness and optical

absorption. The detectability of closed surface cracks in glasses and

ceramics using thermal wave analysis is also being investigated.

Glass Standards

D. H. Blackburn and D. A. Kauffman

Work has progressed in the development of microspectrofluor Imetr Ic

standards for instrument calibration in immunochemical analysis.

Fluorescent glass microspheres 5 to 20 micrometers in diameter, containing

U^Og, MnO , Tb20-^ and have been produced and evaluated.

Consideration is being given to Issue these fluorescent spheres as SRM's.

7
TRIBOLOGY Ronald Munro

Tribology is an interdisciplinary research activity concerned with the

scientific aspects of the measurement and analysis of the friction and wear

of materials and the control of those processes through lubrication. The

applications of ceramic materials for which tribological factors are highly

significant include low heat rejection engines, bearings, cutting tools,

and a multitude of component parts for various engines and other mechanical

apparatus. Neglect of tribological factors can have an immediate impact

resulting in monetary costs, energy consumption, material losses, diminished production time, and reduced equipment efficiency. Improved understanding of tribological factors, therefore, may lead to a multifaceted

savings for the national economy and may aid the position of U.S. industries vis a vis foreign competition. Such competition is being experienced

most keenly in the developing applications of advanced ceramic materials.

The tribological challenges encountered in the use of ceramics have

motivated a technical program for the Tribology Group that encompasses

three inter-related components. A prototypic tribological contact consists

of two solid material bodies in relative motion interacting across an intervening lubricating medium in the presence of a local atmosphere. As a result of the interactions, the contact region may have relatively high

temperatures and stresses. Thus, the material properties, wear mechanisms,

and friction characteristics of the solid bodies form one important area of

study. The variations of the chemical and physical properties of the

lubricant form the second aspect of the program, while the interactions of

the ceramic substrate and the lubricant form the third part. In all cases,

the emphasis of the research effort is on understanding the mechanisms of

the various processes.

Representative Accomplishments

o A new wear test method has been developed for the study of the

friction and wear characteristics of ceramic materials. The new design was produced through a modification of the widely available

four-ball wear tester to yield a ball on three flats configuration.

The advantages of the new design include a greater flexibility in the

source of ceramic specimens, easier sample preparation, and a sample

geometry that is more amenable to pre- and post-test surface

analysis.

o An important step was made towards the establishment of an international standardization of wear test methods through participation in

the Versailles Project on Advanced Materials & Standards (VAMAS).

Measurements on the series of materials in the round-robin testing

included friction, wear, surface prof ilometry , and scanning electron

microscopy of the prepared and worn surfaces.

o A new technique, incremental isothermal thermogravimetric analysis

(I 2TGA), nas been developed as part of a study of high temperature

characteristics of lubricants for ceramic heat engine applications.

The I 2 TGA technique provides a rapid determination of evaporation rate

as a function of temperature and the corresponding activation energy.

8
Such measurements are valuable in the assessment of lubricant

volatility and are important to the control of oil consumption and

volatility wear in ceramic heat engines.

o Two standard reference materials (SRM) were issued and made available

for purchase through the Office of Standard Reference Materials. SRM

1818 and SRM 1 8 1 9 were developed as measurement reference materials

that may aid the determination of small amounts of chlorine or sulfur

in a lubricating base oil or similar material.

Wear Teat Methods for Ceramic Materials

R. S. Gates, J. P. Yellets, D. S. Lim 1

, F. Wang2

, 0. Vingsbo^,

. and R e G. Munro

1 Guest Scientist, University of Illinois

2 Guest Scientist, Tsinghua University

^IPA , Uppsala University

Ceramic materials are presenting a wide range of new and unusual challenges

to the field of tribology. Underlying many of these challenges are the

material properties of the ceramics, particularly the microstructure.

Numerous results have shown that the performance of a ceramic material in a tribological context can vary dramatically from batch to batch of material

production, even when customary and reasonable quality assurance practices

are followed. Consequently, the need for wear test methodology that

incorporates analyses of microstructural effects is quite apparent. This

situation differs markedly from the more traditional wear testing of metals

where batch to batch variations were minimal. One result of this difference is the immediate need for the design of wear test apparatus for which

the test specimens may be readily subjected to pre- and post-test surface

analysis techniques. Efforts to fulfill that need have been made during

this fiscal year. Interests in the standardization of wear testing imposed

further constraints on the design of the new apparatus. The availability

of the apparatus and the configuration of the sample interfaces were also

important. Such considerations led to a new design in the form of a modification of the widely available four-ball wear tester. By redesigning

the sample chamber such that the three stationary balls were replaced by

three flats, a ball on three flats configuration was produced. The new

design meets the primary technical requirements for ceramic wear testing

while providing a technique that will be widely available at relatively low

cost. Tests on measurement repeatability have shown that both friction and wear determinations were repeatable within five percent.

Lubrication of Ceramic Materials

P. Pei, C. S. Ku, K. L. Jewett, L. S. Hsu, D. E. Deckraan, R. S. Gates,

and R. G. Munro

The control of wear in ceramic devices such as heat engines requires the

use of a lubricant capable of sustained operation at high temperature. The

minimum requirement for a short-term near-future lubricant is operation at

intermediate temperatures to MOO °C. Current automotive lubricants have

9
limiting peak temperatures of about 250 °C for short duration. The

principal concerns for high temperature lubricant operation are oxidation,

thermal degradation, volatility wear, and chemical corrosion. These

processes are directly related to lubricant effectiveness, lubricating film

formation, sludge or harmful deposits, and oil consumption. Under

in-service conditions, lubricants evolve through a complex series of

molecular structural changes resulting from heating and chemical reactions.

The net effect of the process is a degradation of the lubricant effectiveness, i.e., a reduction in the ability of the lubricant to afford protection to the tribological surfaces undergoing wear. This degradation

process is strongly dependent on the temperature and is accelerated by

elevated temperatures. The changes in molecular structural composition may

be considered as the results of two types of processes: thermal, such as depolymerization, and chemical reactions, such as oxidation. The thermal

stability of a lubricant is the intrinsic capacity of the lubricant to

resist molecular structural changes under heating in the absence of

oxidation. Oxidation reactions in lubricants tend to accelerate viscosity

increases, corrosion, wear, and the production of sludge-forming deposits.

Hence, both thermal and oxidative stabilities are principal aspects of

advanced lubrication concepts. Efforts to develop suitable measurement

capabilities have led previously to several complementary techniques

including a novel temperature scanning thermogravimetric analysis (TGA)

procedure, differential scanning calorimetry, micro-oxidation testing, and

oxygen uptake tests. A new technique, an incrementally isothermal TGA

procedure, has been developed to study the volatility characteristics of

candidate high temperature lubricants. The new measurement technique

provides a rapid determination of evaporation as a function of temperature

and the corresponding energy of activation. Results from the new technique

will provide key data to be used in conjunction with thermal, oxidative,

and wear test results to develop and understand high temperature lubrication concepts and ceramic-lubricant interactions.

Standard Reference Materials

P. Pei, C. S. Ku, L. S. Hsu, K. L. Jewett, and R. G. Munro

Standard reference materials (SRM) are a vital part of measurement

tecnnology and are often crucial to the calibration of industrial instruments or for the quantitative interpretation of analytical data. The

development of a series of such SRMs for use with automotive lubricants has

been undertaken as part of an ongoing effort to improve analytical procedures for lubricant analysis. A goal of the project is to produce three

calibration standards that will enable quantitative measurement of three

important elements that frequently occur in relatively low concentrations:

chlorine, sulfur, and nitrogen. Two of these standards, SRM 18 18 (chlorine) and SRM 1819 (sulfur) were released for sale during this fiscal year.

Work is continuing towards a standard for nitrogen in base oils. Other

work on reference materials included the production of a new batch of SRM

1817, a fuel and metal catalyst package for oxidation testing of automotive

lubricants. The stock of the original 1000 units issued in 1983 was depleted in early 1986 because sales of the SRM were relatively rapid as a result of world-wide use of the MBS developed thin film oxygen uptake test.

Certification testing of the new batch of SRM 1817 is in progress.

10
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.

Two principal areas of optical materials research are being covered:

Thin optical films addresses structure/processing relationships and

how they affect properties and performance as related to optical

coatings and integrated optics.

Materials for optical signal processing addresses

structure/processing relationships of crystalline electro-optical

materials important as modulator and optical memory materials.

In addition to the principal areas of activity, the group maintains the

capability to measure refractive index, thermo-optic constants and

piezo-optic constants of optical materials.

Representative Accomplishments

o Transmission electron microscopy (TEM) and x-ray diffraction (XRD)

studies of electron-beam evaporated zirconia optical films show that

the film microstructure is in the form of conical columns. These

results explain both the change of crystal structure with distance from

the substrate and the refractive index inhomogeneity of zirconia films.

Mixed zirconia-silica films observed to be amorphous by x-ray

diffraction have been shown to be amorphous by electron diffraction as well.

o Apparatus that uses photo-thermal radiometry (PTR) to measure the

thermal properties and adhesion of thin films has been constructed.

Delamination of films from substrates is clearly observed when a suitable shear stress is applied to the thin film-substrate specimen.

Measured thermal diffusivities agree well with values in the

literature.

o Synchrotron topography at the National Synchrotron Light Source (NSLS)

of Czochralski-grown bismuth silicon oxide (BSO) has shown elaborate

arrays of defects associated with growth irregularities. The detailed

understanding gained in collaboration with crystal growers should lead

to greatly improved optically active materials.

11
Thin Optical Films

A. Feldman, E. N. Farabaugh, Sun Yining 1

, H. H. Chen2, R. Gomez Barengo^

1 Guest Scientist, Lanzou Institute of Physics, Peoples Republic of China

2 Guest Scientist, Precision Instrument Development Center, Taiwan

^Guest Scientist, Instituto Politecnico Nacional. Mexico

The microstructures of thin films of ZrO£ and Zr02"Si02 formed by

electron-beam coevaporation have been examined by x-ray diffraction and

transmission electron microscopy (TEM). The films, which ranged in

thickness from 10 nm to 150 nm, were grown on mica substrates coated with

carbon. The substrate temperature was 325 °C. For the TEM studies, the

specimens were placed in water which caused the films to separate from the

mica substrates. The films were allowed to settle on copper grids.

Results of the TEM examinations suggest that films composed of 100? Zr02

grow by the formation of conical polycrystalline columns. Near the

substrate the columns are of small diameter and contain a single

crystalline phase, but at increasing distances from the substrate the

column diameters increase and material with two crystalline phases occurs. Electron diffraction suggests that an amorphous phase is also present

adjacent to the substrate. Small additions of SiOg to the film

composition result in a smaller column diameter at a given distance from

the substrate. Films with greater than 30? Si02 by volume, which display

an amorphous x-ray diffraction pattern, have been shown to display an amorphous electron diffraction pattern as well. The surfaces of the

amorphous films are nearly featureless and are significantly smoother than

the surfaces of 100? Zr02 films. This work will assist in the development

of optical films with greater optical and mechanical stability.

Materials for Optical Signal Processing

B. Steiner

Monochromatic topographs of several slices of a single high quality

bismuth silicon oxide boule show complex strain patterns indicating

previously unsuspected irregularities in Czochralski growth nominally

under effective control. These features can be compared to provide a detailed understanding of their development. For example, the prominent

strain on the right edge of the fringed central square in Figure A, a Bragg topograph from the NBS beamline at NSLS, is shown in Figure B, a corresponding Laue topograph also from the NBS line, to be due to the . temporary cessation of growth in the peripheral region on the right. The

central area, growing in the [001] direction, and the three other

peripheral regions growing in the [011] direction meanwhile continued to

grow in step with each other in the [001] direction. Three successive,

dark [011] planes toward the top of Figure B can be observed to Intersect

the halted [011] plane on the right in the form of characteristic angles

formed by the critical interface and the bottom edge of the slice. From

such detailed studies, in which the Laue geometry permitted by the

intensity of the synchrotron is crucial, crystal growth by many differnt

techniques is expected to yield optically active materials of greatly

improved quality.

12
Photo-thermal Radiometry for Measuring Thermal Properties and Adhesion of

Thin Films

Ho P. R. Frederikse and A. Feldman

A principal goal of this project is to put the measurement of the adhesion

between a film and a substrate on a more quantitative basis. We want to

measure the adhesion of coatings as a function of surface condition,

substrate temperature and deposition technique. The system under

investigation is a dielectric film (1-100 pm thick) on a metal substrate.

Delamination is brought about by stressing the sample in a calibrated

bending device. For detecting the onset of delamination we use a thermal

wave technique known as photo-thermal radiometry (PTR). This method uses

a chopped laser beam to produce a modulated temperature at the surface of

the film. The heated spot on the specimen is focussed onto an InSb

infrared detector which monitors the amplitude and phase of the

temperature at the specimen surface. The phase of the signal is sensitive

to inhomogeneities in the specimen, like voids at the interface. By

translating the specimen across the beam one can map variations at the

film-substrate boundary. We have performed a series of scans of specimens

under increasing flexural loading and have observed the initiation of film

break-up or delamination. Films currently being investigated are plasma

sprayed chrominum-oxide and magnesium zirconate on aluminum (-50 ym

thick)

Another goal of this project is to measure the thermal diffusivity of thin

films. This measurement is important in the case of films subjected to

thermal loading such as optical films in high power laser beams. This

property can be correlated with the density (porosity) of films. In the case of films of mixed composition, the measurements can be correlated

with models for the thermal behavior of mixed films. In this case, the

method of measurement requires measuring the thermal signal as a function

of chopping frequency which varies the diffusion length, and, hence, the

probing depth of the thermal wave. Trial measurements of thermal

diffusivities indicate good agreement with the literature.
Figure 1 B. Laue topograph of crystal shown in Figure A.

Figure 1A. Bragg topograph of bismuth silicon oxide crystal.

14
STRUCTURE/STABILITY

HIGH TEMPERATURE CHEMISTRY John Hastie

Our program in high temperature chemistry and phase equilibria emphasizes the

structural, thermodynamic, and chemical-kinetic behavior of materials in

high-temperature/high-pressure (gaseous) process and service environments.

Solid-liquid-vapor phase equilibria, crystal and molecular structure, and

reaction mechanisms of ceramic, glass, slag, salt and other inorganic systems

are determined experimentally and through modeling. The Phase Diagrams for

Ceramists Data Center compiles and critically evaluates ceramic phase

diagrams in cooperation with the American Ceramic Society.

This activity serves new technologies, such as those based on processing of

advanced ceramics, refractory ceramic durability, nuclear waste management,

electronic ceramics, and more efficient fossil fuel combustion. Industry and

other government agencies use the results (a) for performance predictions and

test method development in new high technology applications, and (b) to

support materials processing at high temperatures.

The research addresses: development of new or improved experimental methods,

their application to determination of basic data and new concepts, modeling

of ceramic/metal gas-liquid-solid equilibria, and computer-aided critical

evaluation and compilation of ceramic phase equilibrium diagrams.

Molecular-specific experimental methodologies and theoretical modeling tools

are also being developed and applied to the determination of basic

thermochemical and kinetic data and chemical reaction mechanisms. In support

of phase diagram determinations, and for the completion of thermodynamic

cycles, the characterization of condensed phase composition and structure is

achieved by x-ray or neutron diffraction, scanning and transmission electron

microscopy, and electron spectroscopy for chemical analysis (ESCA).

During the past year, the research has focussed on six interrelated sub tasks:

(1) Phase Diagrams for Ceramists Data Center; (2) Phase Equilibria and

Structural Chemistry; (3) High Temperature Chemistry; (4) Data Center on Materials and Components for Fossil Energy Applications; (5) High Temperature

Thermophysical Properties; and (6) Steel Slag-Refractory Thermochemistry , a new initiative. The following discussion highlights some of these areas.

Representative Accomplishments :

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

(ACerS) program for a ceramic phase diagram data center, completed the

first full year of its expansion plan. Novel procedures were

developed and implemented for computer storage and retrieval of

bibliographic files, ternary diagram digitization, computer editing,

topographical manipulation, and for preparation of production-quality

ceramic phase diagrams. A bibliographic data bank for oxide and

salt-containing phase diagram literature was completed and a hard-copy

volume published. A graphics data bank containing about 2000 binary

and ternary phase diagrams was also developed.

15
o A book on "Construction Materials for Coal Convers Ion-Performance and

Properties Data" was published. This activity represents an evaluated

compilation of data provided by the Department of Energy materials

research contractor's reports. The book completes the series covering

alloy and ceramic materials.

o A predictive oxide phase equilibria model, developed earlier, was refined for steel making applications and modified for use by

non-experts. The computer-based model was transferred to several

industries Involved with steel production and coal conversion

(magneto-hydrodynamic, fluidized bed combustion) for use in process

design.

o Basic vaporization data and processing mechanisms were determined for

simulated nuclear waste under high temperature processing conditions.

This work was supported by the Dupont Atomic Energy Division, Savannah

River Laboratory, to provide key vaporization-loss data for the waste

vitrification process being developed by Dupont. The significant

cesium vapor transport found was particularly enhanced by the presence

of the process impurities carbon, halogen, and water vapor.

o The first direct measurement of the enthalpy of melting for tungsten

was determined using a unique levitation calorimetric technique. The

result should serve as a benchmark for testing new phase transition

theories, including melting. The work, performed collaboratively

between NBS, General Electric, and Rice University, also demonstrated

proof-of-concept for levitation of molten materials in space. A

prototype apparatus for space flight experiments was also developed.

o The preparation of single crystal compounds in the Ba-Sm-Ti-oxide

system, together 'with their structural determination, has led to

Industrial development of a new ceramic dielectric. The dielectric,

based on Ba^SmTiqC^, has a very low dielectric loss, essentially zero temperature coefficient in the dielectric constant, and about twice

the dielectric constant of any microwave ceramic filter device

currently on the market. This development resulted from a collaboration between NBS, industry and various national and

international university groups.

Phase Diagrams for Ceramists Data Center

J. W. Hastie, H. M. Ondik, R. S. Roth, L. P. Cook, M. A. Clevinger, M.

Lukens, P. K. Schenck, H. Parker 1

, P. Davidson11 J. Dennis 2

, T. Brittle 2, S. Cauley^, R. Yan^, M. Pryor^, M. Rodtang^,

P. O'Neil^, K. Davis^, and C. Messina2

1 Guest Scientist, NBS, American Ceramic Society.

2 Research Associate, American Ceramic Society

^Student Research Associates, American Ceramic Society

^NRC Post Doc

NBS has a well-established joint data activity with the ACerS and is closely

coupled with current needs, as identified by NBS and ACerS advisory

committees. Recent research activity in this area has been expanded in

response to the increased complexity and quantity of new phase diagrams,

16
together with an expanded dependence by industry and others on critically

evaluated diagrams and related thermodynamic data, and include the following

tasks:

(a) Evaluation/Production . Considerable progress has been made in the

preparation of new "Phase Diagrams for Ceramists" volumes for oxides,

oxygen-containing systems, sulfides and halides. About 6800 phase diagrams

are being evaluated for these volumes and an anticipated NBS completion date

for the next volume is December 1986. Literature search and reference

recovery is also in progress to include new systems containing Periodic Table

Groups IVA, VA, and VIA elements (including many semiconductor compounds) and

also boride, nitride, and carbide compounds.

(b) Data Base Development . Progress has continued both in software

development and in file building for the bibliographic and graphics data

files. The bibliographic file software, developed in collaboration with the

NBS Office of Standard Reference Data, has been expanded and revised. The

software provides not only for the preparation of fully transportable data

files (all ASCII characters) of totally variable length but also for the

generation of files to feed other data bases and any rapid-search data base

management system. The software also provides methods for easy updating,

editing and rearranging of the data elements. The graphics input and editing

software has been expanded so that ternary diagrams are being digitized

routinely. The utility of the ternary phase equilibria data is being greatly

enhanced through development of a general purpose rotate and section program

for three dimensional (3D) ternary diagrams. Figure 2 shows a representative

example of one of the many views possible for a 3D phase diagram constructed

from the planar-projection ternary and binary diagrams. About 1000 binary

and ternary diagrams have been digitized, edited and filed in a computer

data bank.

(c) Modeling/Optimization . Current activities focus on: (1) the

development of new solution models for phase diagram optimization and

prediction (2) incorporation and testing of NBS-developed solution models,

and others, into existing computer codes for phase diagram optimization,

(e.g.; with K. Spear, Penn State), (3) application of the THERMFACT computer

code, with its extended regular solution model, to phase diagram optimization

for relatively simple molten salt systems, (4) development of a thermodynamic

data base for complex oxide systems, for use with the SOLGASMIX (Ericksson,

Sweden) and other computer codes applicable to phase equilibria predictive

modeling, and (5) development of solid-solution models for complex oxide

systems. Progress in each of these areas has been documented elsewhere in

reports, archival publications, and through invited talks.

Phase Equilibria and Structural Chemistry

R. S. Roth, L. P. Cook, E. R. Plante, K. Davis^ , R. J. Cava^ , H. Parker^,

P. K. Davies^, L. Ettlinger^

1 Student

^Guest Scientist, AT&T Bell Laboratories

^Guest Scientist, NBS, American Ceramic Society

^Guest Scientist, University of Pennsylvania, Philadelphia, PA

^Research Associate, JCPDS

17
Experimental research, performed as indirect support of the Data Center

program, and for Other Agency projects, includes both classical determination

of phase diagrams (i.e., direct phase identification) and indirect

measurement based on Gibbs energy relationships. In the latter case, use is

made of vapor pressure measurement using unique NBS facilities developed

under the High Temperature Chemistry program. The classical phase equilibria

program currently emphasises oxide systems important to advanced ceramic

technology. One example is shown in Figure 3 for the very complex system

BaO-Ti02~Nb20q. This system is very important for the understanding and

development of microwave dielectric ceramics with high dielectric constants

and low dielectric loss and temperature coefficients.

(a) Stored Chemical Energy Systems (SCEPS); The LioOAloO? system. During

the past year, work was performed in response to basic data needs of the

Office of Naval Research (ONR) and Garrett Corporation for development of

stored chemical energy propulsion systems. The system of interest is based

on the exothermic reaction of a Li/Al alloy with steam to yield L^O-A^Oj

phases and hydrogen, which is to be burned for additional thermal energy.

Also, the join LiA102-Al203 is of particular interest to the aluminum

industry for production of ceramic crucibles used in the processing of

lithium-aluminum alloys for aerospace application.

(b) Thermogravimetric Study of SCEPS Oxidation Reactions . In addition to the

detailed work on Li 2o-Al20

3 discussed above, exploratory studies of eight

alternative stored chemical energy systems have been conducted. The aim of

these studies was primarily to determine the reaction kinetics and products.

The reaction products involve complex phase relations among mixtures of

salts, metals and oxides. The eight fuel/oxidant reaction schemes of

interest are: Li/H20; H2 /02 [-1], Li/H20; Na02 /H2

0; H2 /02 [2], MgAl/H2 0; H2 /02

[3], UAI/CIO3F [4], LiAlMg/ClOoF [5], LiBe/ClOoF [6], Li/C n F20 [7], and

LiB/NF^ [8 ].

(c) Ceramic Dielectric Barium Polytitanate Systems . A small amount of Nb2 05

is often added for commercial preparation of BaTiO^ ceramics in order to

optimize the dielectric properties. Electron diffraction has shown that a second phase exists in the grain boundaries which is not the polytitanate

Ba^Ti-jYOijo (6:17 oxide mole ratio) known to be in equilibrium with BaTi0

3 in

the binary system. Investigation of the ternary Ba0-Ti02 -Nb205 has shown

that at least four new phases exist in this system with less than 5 mol

percent Nb205. They have been tentatively identified from single crystals as

Ba6 Ti 1

4

Nb2°39 (8“layer orthorhombic), Ba-| i|Ti4QNb20g9 (20-L orth),

Ba 10 Ti 28 Nb2^12 monoclinic) and Ba-j sT^ijNb^-j 32 (13“L mon).

Investiga-tions in the ternary systems Ba0-Ti02-Sn02 and Ba0-Ti02 “Zr02 have

proven the existence of the compound Ba2Ti5012 - This phase is apparently

only stable under high temperature when Zr02 is incorporated in the lattice.

The true composition is thus Ba2

T-|5_ xZrx0i 2

» The unit cell dimensions and

crystallographic symmetry were characterized from single crystals.

High Temperature Chemistry

J. W. Hastie, E. R. Plante, D. W. Bonnell, P. K. Schenck, A. B. Sessoms,

M. Wilke

This activity develops and applies new or improved measurement techniques for

the molecular-level analysis of high temperature vaporization and

condensation processes. The processes occur over ceramic solids and melts.

18
coal slags, glasses, and salts and in process atmospheres containing

reducing, oxidizing, carbonated, halogenated, sulfated, hydrous, and other

reactive components. These environments are characterized bv extremes of

temperature (typically 10 - 5000 K), gas pressure (10 - 10 atm), chemical

reactivity, and phase complexity. The conditions and data obtained are

generic to high temperature ceramic processing environments, and in

applications where hot corrosion and high temperature oxidation are materials-limiting factors. Representative activities are as follows:

(a) Nuclear Waste Glass Processing . Industrial and DOE plans for nuclear

waste storage require the waste to be incorporated into a borosilicate glass.

Vapor pressure data are needed for these glass-waste forms in order to

optimize the process conditions (e.g., temperature, composition) and minimize

the loss of radionuclides by vapor transport during the high temperature

processing of the wastes. In earlier NBS work the vaporization losses of

radionuclides was determined for the final process glass at temperatures

around 1100°C. Recent studies have dealt with the pre-glass forming stage at

temperatures between 200-1 000 °C. Using Kundsen effusion and transpiration

mass spectrometry, significant transport of Cs was found and its mechanistic

relationship to the presence of H

20, halogen, and carbon process-impurities

established.

(b) Laser-Induced Vaporization Mass Spectrometry . Degradation of materials

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

fusion processes, laser welding, laser processing of ceramics, laser etching

of semiconductor components, and in the durability of refractories in defense

and space applications. In addition, the use of lasers as point heat-sources

has the potential for characterizing materials phase transformations at very

high temperatures and under essentially containerless conditions. We have

undertaken fundamental studies of laser-induced molecular level vaporization

with initial emphasis on graphite, boron nitride and other refractory

materials.

(c) Ultra-High Molecular Weight Mass Spectrometry — Application to The

Cluster State of Matter . The unique capabilities of the high temperature

mass spectrometry laboratory are being extended to include the very high

molecular weight (up to 20,000 amu) cluster intermediate species present as condensation nuclei! in supersaturated vapors. A reflectron tirae-of-f light

(T0F) mass spectrometer has been designed for this application and

construction is progress.

(d) Steel Slag-Refractory Thermochemistry . During the past year, a new

project was begun as part of the NBS Steel Research Program. This work

represents an extension of our earlier modeling work which focussed on MHD

slags. The objective is to develop a generally applicable computer-based

model of slag-refractory thermochemical Interactions. To-date an experimentally validated multicomponent equilibrium model has been developed

for any solid or liquid-containing mixture of Na

2 0 , K

2 0 , CaO, MgO , FeO

,

Fe

2 0^ , Fe^Oj^, A1 2 0 ^ , and Si0 2

.

19
BaO

(B) 31

cnin^'

CD CD 0a n

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09

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OQ CQ

O 2

03 E S3 s as O' V

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(30

20
NATIONAL BUREAU OF STANDARDS

AMERICAN CERAMIC SOCIETY . PHASE DIAGRAMS FOR CERAMISTS

1650

1550

1450

1350

1250

1150

1050

950

850

750

725

Figure 2„ Computer constructed three-dimensional phase diagram representation,

based on the planar-projection ternary and binary diagram data.

21
STRUCTURAL CHEMISTRY Stanley Block

Knowledge of effects of high pressure and temperature on the structure, phase

relations, and physical, mechanical and chemical properties of materials is

necessary for their efficient industrial utilization. Such information is

essential for improving our understanding of the parameters that are critical

to ceramic processing and transformation toughening in order to produce more

fracture resistant ceramic products. The stability and retention of high

pressure phases as toughening agents to improve the properties of materials,

particularly ceramics is a new area that requires attention. To carry out

these investigations effectively, we must also improve our measurement and

standards capability at high pressures.

Representative Accomplishments

o The critical variables to retain potential transformation toughening

high pressure phases were determined using the high pressure form of

zirconia as a model material.

o Comparative sintering studies of pure and doped zirconia showed that

the toughness of zirconia compacts sintered at high pressure is due to

the high pressure phase serving as a new toughening agent and not

pressure sintering.

Pressure Transformation Toughening

S. Block, G. Piermarini

The question of whether the improved toughness of zirconia samples sintered

at high pressure and temperatures below 500°C was due to pressure sintering

or transformation toughening was solved by comparing yttria doped zirconia,

which has no high pressure form, with pure zirconia. Fig. 4 illustrates the

indentation patterns for the pure and doped materials under identical

conditions, 8.6 GPa and 250°C for 1.5 hours. Although of only slightly

greater hardness (10.3 GPa for the pure versus 8.9 GPa for the doped

zirconia), the pure material is much tougher than its doped counterpart, as evidenced by the distinct lack of radial cracking at the impression corners. This superior toughness is attributable to the presence of the high pressure

metastable phase and not pressure sintering. The above study (carried out in

collaboration with B. Hockey and B. Lawn of the Mechanical Properties Group)

opens up the prospect of using high pressure methodology as an investigative

tool in the search for new transformation toughening agents in ceramics.

Investigations to determine the mechanisms involved in retaining the high

pressure phase of zirconia were conducted. Pressure was used for the driving

force for the transformation, while temperature was used solely as a means of

modifying the extent of the defect population participating in the nucleation

22
of the transformation. Samples of particle size of about 0.03 ym (sample 1)

and larger 0.1 urn (sample 2) were treated by the routes shown in Fig. 5.

Different processing of zirconia powders resulted in retention of different

amounts of the high pressure phase. In (a) the retention was 40% for

sample 1 and zero for sample 2. For (b) retention was 100% for sample 1 and

50% for sample 2. For (c) the retention was 20% for sample 1 . The dashed

lines indicate the boundary between the high and low pressure phases for

forward and reverse transformations.

We can draw the following conclusions from the experiments:

(1) Thermal treatment, hydrostatic environment, and particle size are all factors which influence the retention of the metastable high

pressure phase.

(2) The results support the idea that the transformation is initiated

at nucleation centers whose potency can be minimized by thermal

treatments.

The other aspect of this program is the search for new transformation

toughening agents. Crystal chemical principles can roughly guide the search

and once a candidate material has been found can suggest substitutions to

reduce the transition pressure. The transition pressure of several compounds

were determined. Some were promising and suitable analogues and solid

solution series were prepared by L. Cooke, R. Roth and K. Davis of the High

Temperature Chemistry Group. As anticipated, the transition pressure was inversely related to ionic size. Potential toughening agents which transform

in the 0.5 to 1.5 GPa range, significantly lower than for zirconia, were

found. Currently studies are underway to evaluate their toughening ability.

Kinetics of Decomposition of High Energy Materials as a Function of Pressure

G. Piermarini, S. Block and P. Miller1

1 Naval Surface Weapons Center, White Oak, MD

This project, which is funded by the Army Research Office, is designed to

provide information on the parameters that affect the kinetics of thermal

decomposition of high energy materials. The study of the phase behavior,

melting point and decomposition of HMX as a function of pressure and

temperature were carried out. The results are in the process of being

published.
Fig.

4

Indentations

on

Compacts

Prepared

at

P=8.66GPa,

T=250°C,

t-1.5

hrs
Fig 5 Effect of processing route on retention

of high pressure Zr02 phases.

25
Ceramic Powder Characterization Alan Dragoo

Improved characterization of ceramic powders is recognized as one of the key

factors needed to provide "important leverage in overcoming the reliability

and reproducibility problems" in the manufacture of ceramic components for

heat engines. Strength and other performance properties are limited by

process-related flaws. Flaws can result from undesirable characteristics of

the powder and from manipulation of the powder into the pre-fired ("green")

body. Improved characterization of ceramic powders requires not only greater

accuracy and precision in measurement but also a better understanding of how

powder characteristics are related to processing and performance of ceramic

components.

Improvements in powders and powder characterization are expected to have a critical impact on the successful production of ceramic parts for heat

engines. This market is expected to grow from a $56M in 1990 to $840M by the

year 2000 2 . The International Energy Agency (IEA) recognized that powder

characterization was among the critical factors for the development of

ceramic heat engines when it established an international interlaboratory

comparison of physical and chemical characterization methods for ceramic

powders. This group is engaged in the preparation and certification of

several thousand powder samples for this round-robin.

The market for electronic ceramics is expected to grow from $1 ,900M in 1990

to $3»485M in year 2000. Innovations in the use and control of powders

are expected to offer a competitive edge in such areas of electronic ceramics

as thin-layer electronic elements, substrates and mm-wave devices.

Understanding the connection between powder characteristics and processing

and performance begins with the recognition that powders are complex physical

and chemical systems in which characteristics are often spatially distributed

within particles, between interior and surface, and between particles. An

average value alone has little meaning for a characteristic of a powder. The

distribution of a property between particles and within particles needs to be

specified. There is a critical need for Standard Reference Materials (SRM’s)

with certified distributions to be used in the calibration and intercomparison

of instruments for size distribution measurements.

The work of the group is carried out primarily in two laboratories: the

Fine Powder Laboratory and the Automated X-Ray Diffraction Laboratory. This

year a program was inaugurated to expand our capabilities in electron

microscopy/ image analysis.

Representative Accomplishments

o 1500 zirconia powder samples and 9000 silicon nitride powder samples

were prepared and certified for an international round-robin.

o A synthesis method was developed for the preparation of

alkali-stablized tridyraite for a new x-ray diffraction SRM.

26
o Ultrasonic measurements were used nondestructively to evaluate green,

partially sintered and fully sintered alumina compacts containing

hard and soft agglomerates.

o A complete overhaul of the x-ray diffractometers was performed.

Powder Characterization

C. Robbins, J. Kelly, D. Minor, A. Dragoo, J. Sung (Student)

Research is carried out with a variety of methods, including x-ray sedigraph,

photon correlation spectroscopy, Brunauer-Emmett-Teller (BET) surface area

measurement, mercury intrusion porosimetry and density measurement. Powders

are characterized as part of research efforts in ceramic processing, for

studies of wear of ceramic components, and for certification of powders for

interlaboratory comparisons and as Standard Reference Materials (SRM).

Sources of variability in measurement of powder characteristics are being

investigated for several alumina and silicon carbide powders. Preparation of

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

under the auspices of the IEA has constituted a major effort in subdivision

and packaging. The assurance of physical and chemical homogeneity between

samples is critical to the success of the round-robin.

Electron Microscopy/linage Analysis

J. Kelly, D. Minor, A. Dragoo

Indirect methods of particle size measurement generally yield a size which is

computed from a size-related phenomenon, such as sedimentation rate. The

accuracy of indirect measurements depends on the validity of the algorithm

used to compute the size and on the influence of other particle

characteristics, such as shape, on the measurement. Direct characterization

of particles can provide fundamental size and shape data to verify the

physical assumptions underlying the indirect methods. For ultrafine

particles scanning electron microscopy (SEM) and transmission electron

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

achieve measurement standard errors of a few percent, on the order of 10,000

images may have to be measured. Consequently, automated image analysis is

required. A program to expand our capability in this area was initiated this

year.

X-Ray Diffraction

J. Cline, C. Hubbard, C. Robbins, A. Dragoo, Y. Zhang (Student), W. Wong-Ng*,

H. McMurdie*, B. Paretzkin*, M. Morris*, E. Evans*, M. Mrose*

*JCPDS-ICDD Research Associates

The x-ray diffraction program includes the certification of SRM's, the

investigation of material properties, such as residual stress, grain size and

preferred orientation, and the generation of high-quality x-ray reference

data for the Powder Diffraction File. Work on SRM's has focused on the

recertif ication of two reference materials: SRM 640b, a silicon x-ray line

position standard; and SRM 674, a set of five x-ray intensity standards. A synthesis method was developed for the preparation of alkali-stabilized

27
tridymite which is being developed as a quantitative x-ray SRM. A workshop

on Quantitative X-Ray Powder Diffraction Analysis, held on June 23 and 24, was attended by over 170 scientists from industry, government and academic

laboratories. The need for new standards was emphasized in several technical

presentations at the workshop. A new program was instituted with the

International Centre for Diffraction Data (ICDD) for the production of powder

diffraction patterns and data for important ceramic phases. This program

replaces that of the JCPDS-ICDD Research Associated which over the past 30

years has produced many high-quality reference patterns.

Ceramic Processing

C. Robbins, M. Jones (Student), J. Kelly, D. Minor, A. Dragoo

The compaction and sintering of alumina powders consisting of hard and soft

agglomerates were investigated by ultrasonic measurements of elastic

constants. A technique was developed for dry-coupling the ultrasonic signal

to the compacts. A correlation was observed between the elastic moduli and

the density of the samples, with the samples formed from the hard

agglomerates exhibiting lower values for the moduli and density in the green

and partially sintered states. Green state compacts formed from both hard

and soft agglomerates were observed to have negative Poisson's ratios.

Measurements of porosity and surface area of these samples are in progress.

28
SURFACE CHEMISTRY AND BIOPROCESSES GROUP Frederick Brinckman

The Group provides data essential for understanding and quantitating

surface mechanisms of chemical and biological processes that are important

in the processing, performance and durability of inorganic materials. For

many materials molecular surface characterization is a prerequisite for

control strategies based on molecular design. Current project areas

include: quality control measurements for ceramic precursor powders,

microbial processing of ores, performance of organotin antifouling

coatings, and design of tailored phosphors and their performance on postage stamp surfaces. The Group's extensive experience and facilities

in molecular chemical speciation in gas and liquid phases has guided our development of new facilities for surface molecular characterization of

materials, as summarized in Figure 6 .

The Group's critical measurement advances have now made possible the

development of novel standards, especially in the areas of organotin

speciation and microbial ore processing. Increasingly, the international

community in these areas look to the Surface Chemistry and Bioprocesses

Group for needed SRMSc

Representative Accomplishments :

o A novel epifluorescence microscopy imaging (EMI) method has been

demonstrated, in collaboration with the Chemical Engineering Department

at Johns Hopkins University, as an jjn situ probe for characterization

of microbial metal ore processing on mineral surfaces. The technique

is a valuable tool for obtaining a fundamental understanding of

mechanisms of bioadhesion on refractory ore surfaces that affect

bioengineering efficacy, in turn giving us a probe to monitor ore bioprocessing activity.

o Tributyltin (TBT) measurement methods and intercomparisons, environmental fate data, and standards have been delivered to the U.S. Navy in

support of their implementation of organotin based antifouling coatings

for the fleet. This unique information provides the Navy and other

federal and state agencies with methodology for monitoring the marine

environment, environmental fate data for hydrodynamic models, and

research materials for interlaboratory intercomparisons and validations of the necessary measurements.

o Development of a novel, 3 table, water soluble phosphor for postage

stamp tagging has been carried to the implementation stage in FY 1986.

Our terbium complex eliminates the need for organic varnishes and

heterogeneous abrasive inorganic phosphor particles in coating

formulations, allowing for improved stamp visual quality and decreased

wear on facer/canceller machinery.

o Diffuse reflectance Fourier transform infrared spectroscopy (FT-IR) is

the basis for a rapid new measurement technique that quantitates the

amount of 0 -phase present in bulk silicon nitride powder. Monitoring

of % 0 -phase is necessary in Sl^f^ quality control, and this effort

demonstrates the potential utility of surface analysis in a wide

variety of ceramic applications.

29
Materials Processing via Biotechnical Routes

I

I

G. J. Olson, F. E. Brinckman, T. Trout 1

, H, Ehrlich^, H, Blakemore^,

J. S. Thayer 4

, R. M. Kelly-5 , W. P. Iverson®

12

345

6

Graduate Co-op Student, University of Maryland

Guest Scientist, Rensselaer Polytechnic University

Guest Scientist, University of New Hampshire

Guest Scientist, University of Cincinnati

Guest Scientist, Johns Hopkins University

Guest Scientist, NBS, emeritus

Facilities developed by the Group provide a unique capability to

investigate and understand the fundamental mechanisms of bioprocesses for

the selective dissolution and transformation of elements from metal ores

and scrap. With U.S. Navy support we have demonstrated feasible

bioleaching and biorecovery processes for strategic metals to provide new options for reducing National dependence on imported supplies. We are currently participating in the American Iron and Steel Institute -Federal

Laboratory subcommittee on scrap steel recycling investigating novel

bioprocesses for upgrading domestic iron ore (P, Si removal) and scrap

steel (Cu removal) to Improve the competitiveness of the U.S. steel

industry.

The basic mechanisms of ore dissolution by acidophilic microorganisms have

been poorly understood, mostly because measurements of microbial activity

at ore surfaces are exceedingly difficult. With collaborators at Johns

Hopkins University, we developed and demonstrated an EMI method to

quantitate adhesion of ore processing bacteria to ore surfaces. This

method employs acridine orange staining and epi illumination (440 nm) to

indicate cell metabolic (metal releasing) activity based on fluorescence

color of cells. The fluorescence color may be related to intracellular

pH, indicating the metabolic state of the bacteria. Our data support the

theory that organisms attached to ore surfaces are more important to ore dissolution than cells in free solution. Thus, the technique has

important prospects not only for assessing processing status in leaching

systems, but also for investigating fundamental scientific questions

related to the mechanisms of metal ore dissolution by bacteria.

A significant barrier faced by the emerging bioleaching technology is the

lack of standard substrates and standardized bioleaching testing

procedures. New, more effective strains of leaching bacteria are being

sought in the environment and developed in the laboratory by selective

culturing or, in the future, genetic engineering. Consequently, we are working with OSRM to develop metal ore (sulfides) SRMs as standard

substrates for bioleaching studies. In addition, the new ASTM Committee

E-48 on Biotechnology formed a task group for developing standardized

procedures for testing ore bioleaching with group member Olson serving as chairman. NBS SRMs will be important in inter laboratory comparisons of

the standardized leaching procedures.

30
Finally, we applied our sensitive TBT speciation methodology to

investigate the fate of TBT in its service (estuarine) environment.

Lacking a measurement method, Navy models had assumed a relatively slow

degradation (2? per day) of TBT in estuarine waters, causing concern about

TBT persistence and effect on non-target biota. Concurrent work at NOSC

and NBS has radically altered this picture of TBT persistence. We found

TBT half lives of 1-2 weeks in estuarine water samples collected in summer. Algal activity accelerated the degradation to much less toxic diand monobutyltin species. These data have altered the Navy model of TBT

and suggest that at least during part of the year, TBT is biodegraded

relatively rapidly to less toxic species in the environment.

Phosphor Coatings . The Group’s expertise in molecular surface chemistry

has successfully addressed a request by the U.S. Postal Service for

improved, innovative postage stamp phosphor materials and processing

technology. We have developed a method for tagging postage stamps wherein

a homogeneous phosphorescent terbium coordination complex in aqueous

solution is applied to paper substrates. Current tagging technology

requires an abradible crystalline inorganic phosphor heterogeneously

dispersed in organic varnishes. Our invention impinges directly upon the

multi-billion dollar postage stamp industry, allowing for efficient

cancellation, non-abrasion, and high quality, true-colored, varnish-free

stamps.

The pure phosphor is readily synthesized in conventional apparatus. We

have supplied several paper manufacturers with sufficient material for

pilot plant scale paper preparations currently being field tested by NBS

and USPS. Thus far the paper/phosphor combinations have shown excellent

stability toward indoor and outdoor light exposure, and relative humidity

conditions up to 90% . Under prolonged exposure to humidity in the 90-100?

range however, phosphorescence efficiency declines. Two primary

mechanisms contribute to phosphorescence loss: (1) solubility-induced

migration of the terbium away from the stamp surface, and (2) coordination

quenching via ligation of water to terbium.

The migration mechanism can be negated by molecular schemes that

immobilize the phosphor at its intended surface location. Various

chemical and coating strategies accomplish this goal. Quenching by water

is a consequence of vibronic coupling between 0-H stretching modes and the

lowest excited state of the terbium complex, convincingly shown by the

maintenance of stamp phosphorescence in a saturated D

2 0 atmosphere.

Interestingly, however, 100? humidity conditions do not affect the

phosphorescence of pure, crystalline terbium complex samples, indicating

that different coordination environments exist around terbium in the

crystalline state vs. on the cellulosic substrate.

Final data on paper/phosphor stability, toxicity, and economics are being

gathered by USPS and NBS to facilitate implementation of the terbium

phosphor as quickly as possible.

31
Interface Chealstry of Materials

W. R. Blair, E. J. Parks, G. J. Olson,

T. Trout 1

, E. Tierney2

, G. Eng^, C. L.

R. A. Faltynek, F. E. Brinckraan,

Matthias2

Graduate Co-op Student, University of Maryland

2 Guest Scientist, University of Maryland

^IMSE Faculty Appointment, University of the District of Columbia

Qrganotin Antlfoullng Materials . Regulatory decisions by the EPA in the

next 2-4 years will affect marine use of TBT-based antifouling materials

as well as U.S. Navy fleet plans to employ the innovative TBT-based

antifouling polymer coatings, a strategy that would save hundreds of

millions of dollars annually in fuel costs and enhance fleet preparedness.

The Navy, EPA, NOAA, and other agencies conducting TBT risk-benefit

assessments have found only limited environmental data, since measurement

methods for the leached, toxic TBT species at action levels (ng L- ) in

the marine environment have not been available.

For many years the Group has had a world leadership position in developing

measurement methods for the design, characterization, quality assurance

and environmental fate of organotin materials. Group members serve on national (ASTM) and international (EEOGOIPM) committees evaluating

organotin development, use and characterization. We have developed

state-of-the-art methods for both quantitation of organotins and

speciation of tributyltin and its degradation and redistribution products

in seawater at necessary ng lT 1 levels, transferred these techniques to

the Navy, and trained Navy personnel for their monitoring program needs.

EPA, industrial, and university laboratories are adopting NBS

methodologies to initiate monitoring programs for aquatic systems. We

also conducted with the Naval Ocean Systems Center (NOSC) a successful TBT

measurement intercomparison and evaluation of storage procedures with

field samples, demonstrating that reliable data intercomparisons of TBT

concentrations in marine waters are now feasible.

Also important to the rapidly growing number of laboratories involved in

tributyltin environmental monitoring world-wide is the availability of

SRMs . Last year’s report described a measurement methods intercomparison

involving laboratories in 11 nations, employing a high purity, aqueous

research solution of TBT generated chromatographically at NBS. Thus, we found that chromatographic synthesis of organotin solutions represents a reliable and reproducible method for producing very high purity solutions

containing only a single molecular species, with good stability and shelf

life, the attributes necessary for a SRM. We are currently producing, for

the Navy, a mixed butyltin research material for another measurement

intercomparison and will use the chromatographic generator column

technique to produce speciated organotin SRMs. We plan to also use such

generator column technology in the coming year to produce ultrapure

ceramic precursors on a g*-kg scale.

32
Molecular Structural Characterization of Ceramic Precursors

R. A. Faltynek, F. E. Brinckman, T. Trout 1

Graduate Co-op Student, University of Maryland

The ultimate quality of finished ceramic materials depends strongly on the

purity and morphology of precursors used in their production. For

example, silicon nitride powders prior to compacting, must contain an appreciable quantity of B-phase material to yield a product with

acceptable physical properties. A survey of several silicon nitride

powder samples from domestic and imported Sources by diffuse reflectance

Fourier transform infrared spectroscopy showed large intensity variances

in the fingerprint bands assigned to B**phase bending modes between 750-550

cm”1

, with the strongest signal present in the sample known to produce the

best finished ceramic. This prompted us to prepare a working curve

correlating B-phase absorption with concentration that will allow for

future rapid analysis of Si^N^ by FTIR (Figure 7). It is anticipated that

other ceramic powders can be assayed for important functionality in the same manner, and that rapid, non-destructive infrared surface analysis by

reflection techniques will become a significant part of ceramic quality

control.

33
NET

INTEGRAL

VALUE

UNIFIED SURFACE CHARACTERIZATION

TIME: optical transitions to hours

SELECTIVITY: molecular bond or element

SENSITIVITY: 1 0-’* - 1 0"* g SCALE = <1-10 pm

SOLUTION, GAS PHASES

Photoeff ects

Figure 6. Ultratrace chemical speciation in gas and liquid phases is now

integrated with newly developed Group capabilities in surface

molecular characterization. FT-XR and computerized,

quantitative epifluorescence microscopy together provide a unified molecular speciation capability for studying deposition

or release of materials from surfaces involving chemical or biological processes.

CONCENTRATION (weight % Si 3N4 in KBr)

Figure 7. Absorbance vs concentration plots for 3 prominent infrared

bands in microparticulate a, S phase silicon nitride,

illustrating a method for non-destructive analysis of ceramic

powder crystallinity by FTIR.

34
PROCESSING

STRUCTURAL SCIENCE Edwin Fuller

The program of the Structural Science Group is focused on the structures of

ceramic materials and on the relationship of these structures to the

processes that formed them (ceramic processing) and to the properties and

performance that these structures determine. Characteristic structural

features of ceramic materials range from the molecular, or nanostructural

scale to the microstructural level. Important features at the molecular

level include crystalline defects (vacancies, interstitials, dislocations,

etc.); interfaces and grain boundaries; and impurity chemical concentrations.

At the microstructural level important features include grain size and

morphology; second-phase inclusions and pores; cracks; reinforcing phases

such as fibers and whiskers; and distributions of these entities.

Ceramic structures lie at the heart of surmounting the two major impediments

to the production and use of advanced ceramic materials. The first of these

impediments is the ability to capitalize effectively on the unique properties

that advanced ceramics have, or the ability "to use what we have". The

second is the ability, through an understanding of structure/property

relationships, to tailor ceramic properties to a specific application, or the

ability "to develop what we need". Knowledge of ceramic structures addresses

both of these areas. Structures control the properties of ceramic materials

and are determined by the ceramic processing. Understanding of these

connections can lead to "mature", or well engineered materials and to

effective ceramic design.

The research effort has two main areas: Fundamentals of Interfaces, and

Structure/Property Relations. In the first area, interfacial properties,

such as interatomic forces, surface and grain boundary energies, defect

concentrations and formation energies, and impurity species are studied and

related both to ceramic sintering and to brittle fracture. In the second

area, the relations between microstructural features and fracture behavior

are studied (toughening mechanisms at low temperature and creep rupture

mechanisms at elevated temperature).

Representative Accomplishments

o An improved understanding of the importance of chemical composition

on the sintering properties of ceramics through a comprehensive

review of the literature. Key research opportunities have been

identified, which has led to the design and development of an ultra-clean ceramic processing laboratory.

o Theoretical formulation using a lattice statics Green’s function

method to give a formally exact solution for the atomistic structure

of grain boundary interfaces in ionic ceramics. The method fully

accounts for the discrete structure of the lattice and uses the zero frequency limit of the phonon Green function.

35
o An improved technique for measuring and characterizing the strength

of the Interfacial bond between a ceramic reinforcing fiber and the

ceramic matrix of a ceramic matrix composite using an instrumented

Vickers hardness indenter.

Structures and Properties of Ceramic Interfaces

J. E. Blendell and C. A. Handwerker 1

, E. R. Fuller, Jr., V. K. Tewary2

, C. A. Harding, and C. A. Shen

Metallurgy Division, IMSE

2 Guest Scientist, Birla Institute of Technical & Science, Pilani, India

The overall properties and performance of ceramic materials depend crucially

on the structure and composition of interfaces in these materials.

Understanding of these interface structures and their dependence on defects

and composition is vital for the development of advanced ceramics with

improved and tailored properties. Furthermore, as the demands made on these

materials increase, and multiphase materials become technologically more

important, the need for this basic understanding of interface structure and

properties continues to grow. Several research areas in the Structural

Science Group have been addressing these issues.

Interfacial Stability in Ceramics ; Of particular importance to the

properties and performance of advanced ceramic materials, both during the

processing steps that forms them and during use in service, is the stability

of the 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. Thus it is a process that needs to be understood in order to

obtain optimum performance from high technology materials.

In the past year DIGM has been studied in both alumina and magnesia. The

samples have been annealed in the presence of various solutes in order to

induce boundary migration. The experimental conditions have been selected to

test a current model for DIGM, which assumes that the driving force for

migration is the differential strains and strain energy that is developed

during the diffusion.

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 defects and chemical composition. This

research has been conducted in collaboration with a guest worker from the

Birla Institute of Technology and Science, Pilani, India. A formally exact

solution for the atomistic structure of grain boundary interfaces has been

obtained for ionic ceramics using a lattice statics Green's function method.

The method fully accounts for the discrete structure of the lattice and uses

the zero frequency limit of the phonon Green function. This is in contrast

to previous calculations which have used finite clusters of atoms, or are matched to continuum solutions, and thus depend critically on the boundary

conditions.

36
The grain boundary is taken along coincidence lattice sites which are obtained by rotating two imaginary halves of a crystal relative to each

other. Perfect translation symmetry is assumed along the grain boundary

line. This periodicity is exploited by taking a partial Fourier transform of

the Green function. The long-range Coulombic interactions between ions

across the grain boundary have been shown to be effectively dipolar and

higher order polar interactions which makes them relatively short range.

Thus far, the method has been applied to a tilt boundary in the ionic

rock-salt structure of MgO with a simplistic two-body potential.

Sintering of Ceramics

J. E. Blendell, C. A. Handwerker 1

, C. P. Ostertag2

, E. R. Fuller, Jr.,

C. A. Harding, and C. A. Shen

1 Metallurgy Division, IMSE

2Guest Scientist, University of California, Santa Barbara

Impurity Effects : It is well known that impurities can dominate the

sintering and microstructural development in ceramics. However, there Is a lack of quantitative understanding of the mechanisms by which impurities

affect sintering. In order to study the effect of Impurities it is necessary

to produce ceramic powders and compacts with documented low levels of

impurities. This requires the use of clean room processing techniques and

the ability to measure the impurity levels in the samples.

A laboratory for clean room processing has been designed and is being

constructed. This will be used to produce powders with low levels of

impurities. The impurity concentrations of the powders will be measured and

the contamination during processing will also be documented. This is

necessary as it is the impurities present during sintering that affect the

microstructure, and significant impurities can be introduced during

compaction, calcination and sintering.

Grain Growth in the Presence of a Liquid Phase ; The presence of a liquid

phase during sintering, which is common in commercial ceramic materials,

changes the grain morphology and the rate of grain growth. To study this

effect, a known amount of a liquid phase (anorthite) was added to alumina

compacts which contained large single crystal sapphire spheres. The grain

growth rate of both the matrix grains and the large spheres were measured.

It was found that the presence of the liquid phase changed the shape of the

growing grains as compared to the grains when no liquid was present. Also,

while the presence of a liquid phase lowered the grain growth rate, the

addition of MgO reduced the grain growth rate even more. These results give

insight Into the microstructure development when impurities are present.

37
Interfaces In Ceramic Matrix Composites

T. W. Coyle, E. R. Fuller, Jr., C. P. Ostertag 1

, R. F. Krause, Jr.,

S. W. Freiman2

, and A. Gilat^

1 Guest Scientist, University of California, Santa Barbara

2 Glass and Composites Group

^Guest Scientist, "RAFAEL” Armanent Development Authority, Israel

The low and high temperature mechanical performance and structural stability

of ceramic matrix fiber composites is controlled to a large extent by the

structure, properties and stability of the fiber-matrix interface.

Techniques to characterize these interfacial properties and relate them to

the micro- and macro-scale mechanical behavior are required to develop

reliable ceramic composites. The experimental studies have been undertaken

to develop the understanding necessary to bridge the gap between the nature

and behavior of the fiber/matrix interface and the performance of the bulk

composite material.

Three scales of behavior are examined; the mechanical behavior of the

fiber/matrix interface of individual fibers is characterized by an indentation technique utilizing an instrumented hardness indenter; the

interaction of matrix cracks with simple arrays of fibers is investigated

through the use of fracture mechanics specimens yielding controlled fracture

behaviors; and the performance of bulk composites (uniaxial and woven fiber

reinforced materials and whisker toughened materials) is examined in

flexural, tensile and shear failure modes. The performance of bulk

composites are further characterized by examination of the creep behavior and

related stress- redistribution that occurs under load at high temperature.

Stress Induced Phase Transformations

T. W. Coyle, S. Block 1

, G. J. Piermarini 1, and R. P. Ingel 2

Structural Chemistry Group

2 U. S. Naval Research Laboratory

Transformation toughening is now a well-known and effective method for

improving the fracture behavior of ceramic materials. Further understanding

of the possibilities and limitations of the transformation toughening

mechanism requires a better understanding of the thermodynamics and kinetics

of the transformation itself. Studies designed to examine the influence of

mechanical versus chemical driving forces on the transformation behavior of

Zr02 have been initiated. These include: Raman microprobe analysis of the

phase composition in regions of high local stress arising from residual

stresses and in-si tu analysis under applied 3tress; an informal

collaboration with R. P. Ingel of the Naval Research Laboratory to examine

the high temperature mechanical behavior of skull-melt grown crystals of

unstabilized Zr02

; and studies of the pressure dependence of the stability of

the various phases present in doped and undoped Zr0

2 in collaboration with

Block and Piermarini of the Structural Chemistry group.

38 I
CERAMIC CHEMISTRY Kay Hardman-Rhyne

Research and development in ceramics for structural, optical, electronic,

magnetic, and other applications is being directed increasingly toward

improvements in processing science that will permit reproducible production

of defect-free materials. This goal requires extremely sophisticated

microstructural control. It is now recognized that the evolution of

microstructure begins at the very earliest stages of processing, in the

chemistry of powder synthesis, and is carried forward in the subsequent

compaction and densif ication stages to finished ceramic bodies. New

approaches to ceramic synthesis are evolving, based on advanced

molecular-level synthetic, mechanistic, and structural chemistry.

Low-temperature synthetic procedures, such as the "sol-gel" processes, are becoming increasingly important for synthesis of advanced materials, often in

heretofore unattainable compositions. Advanced structural techniques, such

as SANS and high-resolution electron microscopy, are being utilized

increasingly to elucidate the pathways by which molecular structures evolve

into ceramic structures and microstructures.

The program of the Ceramic Chemistry Group is focused on research to

facilitate the application of modern chemical techniques and understanding to

improved processing of ceramics. The Group’s goal is essentially to put more

and better chemistry into ceramic processing. The objectives of the group

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

relating to chemical aspects of ceramics processing needed by industry for

predictive control of new processes and development of new materials.

Current emphasis is on advanced synthetic methods, evolution of structure in

ceramic synthesis, and relation of chemical process variables to particle

characteristics and microstructure.

Representative Accomplishments

o Generation of SiC, TiB2 , and B 4C from precursors prepared at 130°C in

85-90? yield.

o Generation of particulate composite materials including SiC/TiC and

SiC/TiN from low-temperature precursors.

o Application of SAXS, SANS, and chemical techniques to characterization

of structure evolution in sol-gel processing.

Low-Temperature Chemical Processing Routes to Boride and Carbide Ceramics

Powders

J. J. Ritter and N. K. Adams

Conventional procedures for generating boride and carbide ceramic powders are conducted at temperatures in excess of 1500°C. However, the control of

powder purity, particle size and size distribution is difficult under these

conditions. A novel low temperature chemistry has been developed which

permits the synthesis of precursors to boride and carbide ceramic powders in

a controlled fashion at only 130°C. For example, it has been shown that

39
T iC 1 ^ and BClo react with sodium at 130°C in a non-polar solvent to give the

precursor to TiB2

. Similar type reactions with SiCl4 and CCI4 or BCI3 and

CCl^ have produced the precursors to SiC and B4C repectively. The technique

has been extended further to the syntheses of precursors to particulate

composites such as SiC/TiC and SiC/TiN. The highest powder yields are obtained from reactions conducted in a special NBS designed, hermetically

sealed, high shear reactor shown in Figure 8. As precipitated, the

precursors, are amorphous materials which require further heat treatments for

crystallization. Moreover, the chemistry can be extended to any combination

of metal, non-metal or metalloid halides which can be reduced by alkali

metals. Thus, a wide variety of metal-metal, metal ceramic and

ceramic-ceramic materials are accessible through this procedure.

Structural Evolution In Low-Temperature Ceramic Processing

T. D. Coyle, K. Hardman-Rhyne , and E. P. Lewis

Although low-temperature synthesis of ceramic powders and glasses offers

numerous advantages, its use has been largely empirical. A new research

program has been initiated to elucidate the fundamental reaction mechanisms

by which structure evolves in low temperature processing from molecular

precursors to glass or crystalline products in multicomponent systems. The

objective of the work is to define the critical chemical parameters that will

permit predictive control of powder, film and glass processing. Current

research emphasizes processes for synthesis from metal-organic precursors of

multicomponent oxide-systems of interest as electronic or dielectric

materials. Molecular structure and kinetics are being studied, by GC,

spectroscopy (FTIR, NMR); the polymerization of molecular species to

amorphous ceramic precursors and densif ication of sol-gel derived materials

. is being evaluated by SANS methods; and crystallization of amorphous

precursors is being studied by conventional x-ray diffraction techniques.

During the past year the first combined use of SAXS and SANS, along with

chemical techniques, has been applied to structure development kinetics

during sol-gel synthesis of silica precursors. Insights into the kinetic

processes have been obtained by the use of deuterated materials.

40
A. Variable speed electric motor B. Detail of magnetic

Fig. 8. Magnetically coupled, high-shear chemical reactor.

\ 41

RESEARCH STAFF

PROPERTIES/ PERFORMANCE

Mechanical Properties

Chuang, Tze-Jer

Chuck, Leon

Fairbanks, C* J.

Hockey, Bernard

Lawn, Brian R.

o Ceramics

o Diffusional crack growth

o Finite element analysis

o Creep theory

o High temperature mechanics

o Scanning electron microscopy

o Acoustic monitoring of cracks

o Microstructure/strength relations

o Ceramics

o Deformation and wear

o Scanning and transmission electron

microscopy

o Microstructure/strength relations

o Fracture mechanics

o Contact phenomena

o Surface forces in fracture

Roach, David

Tighe, Nancy

Wiederhorn, Sheldon M.

Glass and Composites

Blackburn, Douglas H.

Cellarosi, Mario J.

Freiman, Stephen W.

o Surface forces in fracture

o Fracture mechanics

o Ceramic creep

o Microstructural analysis

o Scanning and transmission electron

microscopy

o Ceramics

o Fracture processes

o Mechanical properties at high temperature

and pressures

o Special glass formulations

o Glass processing

o Glass standards for microprobe analysis

o Glass SRM development

o Glass standards for manufacture and use

o Glass property measurements

o Ceramics and glasses

o Fracture mechanics

o Mechanical properties, environmental

effects

43
Inglehart, Loretta L.

Swanson, Peter L.

White, Grady S.

Tribology

Gates, Richard

Hegemann, Bruce E.

Hsu, Lin-Sien

Hsu, Stephen M.

Jewett, Kenneth L,

Ku, Chia-Soon

Munro, Ronald G.

Pei, Patrick

o Thermal wave analysis

o Nondestructive evaluation

o Ceramic materials

o Ceramic fracture

o Microstructure

o Geologic materials

o Ceramics and glass

o Nondestructive evaluation

o Subcritical crack growth

o Friction and wear of materials

o Wear mechanisms and analysis

o Engine condition monitoring

o Ferrography

o Laser-Raman spectroscopy

o Ultra-fast microwave detection

o Trace laser analysis techniques

o Heterogeneous catalysis

o Lubricant volatility

o Oxidation stability

o Lubricant fractionation

o High temperature lubrication

o Tribology

o Oxidation mechanisms of organic mixtures

o Lubrication and wear mechanisms

o Molecular structural effects on friction

o High temperature ceramic wear

o Organometalllc speciation

o Oxidation kinetics

o Analysis of organic mixtures

o SRM research

o Oxidation kinetics

o Friction and wear test development

o Modeling of reaction systems

o Kinetics of volatility in lubricants

o Theory and modeling

o Tribology

o Molecular dynamics of phase stability

o Temperature modeling of ceramic pairs

o Separation of complex organic mixtures

o Trace organic compound identification

o Differential scanning calorimetry

44
Optical Materials

Farabaugh, Edward N. o Thin film deposition and analysis

o X-ray diffraction analysis

o Scanning electron microscopy

o Surface analysis

Feldman, Albert o Optical materials

o Thin films

o Solid state physics

o Photoelasticity and thermo-optics

o Guided waves

o EXAFS

Frederikse, Hans P. R. o Electrical and mass transport in solids

o Electrical conductivity

o Depth profiling (Rutherford

backscattering)

o Thermal wave analysis

Steiner, Bruce W. o Calorimetric absorption

o X-ray topography

STRUCTURE/ STABILITY

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

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

Ondik, Helen M. o Phase diagrams for ceramists data center

o Materials properties for coal conversion

o Data compilation systems

Plante, Ernest R. o High temperature chemistry of ceramics

o Knudsen effusion mass spectrometry

o Vaporization thermodynamics
Roth, Robert S. o Crystal chemistry of ceramic materials

o Phase equilibria

o Dielectric and ionic conducting ceramics

o Phase diagrams for ceramists data center

Schenck, Peter K„ o Laser spectroscopy

o Temperature measurement

o Computer graphics

Structural Chemistry

Block, Stanley o Properties, structure and polymorphism of

materials at pressure

o Ultra high pressure properties

o Crystallography and pressure phase

relations of ceramics

o Generation/measurement of high pressures

Piermarini, Gasper J. o Pressure/ temperature effects on ceramic

materials

o Generation/measurement of high pressures

o Physical and structural properties of

materials at high pressures and

temperatures

o X-ray diffraction, phase relations,

optical measurements

Ceramic Powder Characterization

Cline, James P.

Dragoo, Alan L.

Hubbard, Camden R.

Kelly, James F„

Minor, Dennis B.

o X-Ray diffraction of ceramics

o Quantitative analysis

i o Characterization of ceramic precursor

powders

o Chemical bonds in solids

o Ceramic powder synthesis

o Crystallite size and residual stress

o Quantitative x-ray diffraction methods

o X-ray diffraction standard reference

materials

o Reference powder patterns

(JCPDS Research Associateship)

o Scanning electron microscopy

o Image analysis

o A-C spectroscopy

o Analytical SEM of ceramics and particulates

o Ceramic composites

o High temperature ceramic synthesis

46
Robbins, Carl R o Fine ceramic particulate properties and

characterization

o Spray drying; powder preparation

o Quantitative microscopy and x-ray

diffraction

o NDE of ceramics

Surface Chemistry and Bioprocesses

Blair, William R. o Ultratrace metals speciation

o Biotransformations of metals

o Environmental durability of coatings

o Molecular surface characterization

Brinckman, Frederick E« o Environmental metal transport

o Organometallic chemistry

o Biological mediation of surface chemistry

o Ultratrace metal speciation

o Materials durability

Faltynek, Robert A 0 o Inorganic molecular synthesis

o Surface and solution photochemistry

o Spectrophotometry

o Heterogeneous catalysis

Olson, Gregory o Metals biotransformation

o Bioprocessing industrial materials

o Epifluorescence microscopy imaging

o Surface modification and bioadhesion

Parks, Edwin J* o Metalloorganic synthesis

o Macromolecular organometallic chemistry

o Metals imaging in coatings

o Ultratrace metal speciation

o Controlled-release and bioactive polymers

PROCESSING

Structural Science

Blendell, John

Coyle, Thomas W.

o Ceramic processing and sintering

o Sol-gel chemistry

o Diffusion controlled processes

o Activation analysis

o Processing/Microstructure/ fracture

relationships

o Stress induced transformations

o Toughening mechanisms in ceramics

47
Fuller, Edwin R.

Krause, Ralph F.

Ceramic Chemistry

Coyle, Thomas D e

Frase, Katharine G„

Lewis, Era

Rhyne, Kay A.

Ritter, Joseph J.

o Atomistic models of fracture and grain

boundaries

o Fracture mechanics of ceramics and composites

o Fracture, environment-assisted

o Mechanical properties at high temperature

o Nondestructive evaluation

o Fracture mechanics of ceramics

o Creep of ceramics

o Chemical equilibria

o High pressure and high temperature conditions

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 Electrical properties

o Ceramic powder synthesis and processing

o Neutron scattering

o Ceramic processing

o Colloid and sol-gel chemistry

o Small angle neutron scattering

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

48
GUEST SCIENTISTS AND GRADUATE STUDENTS

Mechanical Properties

GUEST SCIENTISTS

Bennison, S., Mr.

(Lehigh U)

o Strength and microstructure of ceramics.

Carroll, D., Dr.

(Penn State U.)

o Creep and creep rupture of ceramics.

Chan , H. , Dr

(Lehigh U.

)

o Strength and microstructure of ceramics

Chen , C . F . , Mr

(Univ. of Mich.

)

o Deformation and fracture of silicon nitride.

Lathabai, S., Dr.

(Lehigh U.

)

o Strength and microstructure of ceramics

Sun , J „ , Ms

(Shanghai Inst,

of Ceramics)

o Element analysis of structural ceramics

Glass and Composites

GUEST SCIENTISTS

•

Deshmukh , P . , Dr

(Drexel U.)

o Ceramic matrix composites - processing and property determination

Gilat, A., Mr.

(Israel Ministry

of Defense)

o Fracture behavior of various fiber reinforced

ceramics

Greenspan, D., Dr.

(Accumetrix Corp).

o Relation between surface reaction and crack growth

Inglehart, L., Dr.

(Johns HopKins)

o Develop laser thermal wave lab

49
Legal LeSalle, E. t Mr.

(ESPCI

)

o Assemble and establish a thermal wave imaging lab

Palamides, T. Mr.

(Drexel U.)

o Ceramic matrix composites, processing and property

determination

GRADUATE STUDENTS

Gonzalez, A.

(Penn State)

o Time dependant failure

Nguyen, V.

(U. of PA)

o Thermal wave analysis

Tribology Group

GUEST SCIENTISTS

Danyluk, S„,

(Prof. U. of IL)

o Mechanical and environmental effects in the wear

of ceramics

Jahanmir , S „ , Dr

.

(NSF)

o Research on physics and chemistry of

interacting surfaces

Klaus, E., Dr.

(Penn State U.)

o Lubricant and additive chemistry

Lim, D., Dr.

(U. Of IL) o Wear mechanisms in ceramic pairs

Peussa, J., Dr.

(Helsinki U.)

o Wear of ceramics under boundary lubrication

conditions

Wang, Fu-Xing, Dr.

(U. of Tsinghua)

o Wear mechanisms in ceramics pairs

GRADUATE STUDENTS

Bailey, D.

(Penn State U.

)

o Chemiluminescence and tribochemistry

50
Deckman, D.

(Penn State U.

)

o Vapor phase lubricaton at high temperatures

Yellets, J.

(Penn State U.)

o High temperature tribometny

Optical Materials

Gomez-Barengo , R . , Mr

(Inst. PolitecnicoMexico)

o Optical properties of thin films

Guenther, K., Dr.

(U. of Alabama)

o Thin film deposition and characterization

Laor , U . , Dr

(Nuclear Res. Ctr.-

Negev, Israel)

o Research in crystalline optical materials

Sun , Y. , Mr

o Thin films and surface analysis

(Lanzhou Inst, of Physics,

Peoples Republic of China)

High Temperature Chemistry

GUEST SCIENTIST

Cava , R . , Dr

(Bell Labs)

o Location of light elements in heavy metal oxides

by neutron diffraction

Chang , L . , Dr

(U. of MD)

o Experimental phase equilibria in molybdate and

tungstate systems and also sulfides

Davies, P.,

(U. of PA)

o Defects in microwave dielectric materials

Parker, H., Dr.

(NBS/ACers)

o Assist in compilation, editing, and associated

activities in support of the Phase Diagram

Data Center

Zmbov, K. Dr.

(Boris Kidrich Inst.)

o Investigate the phenomenon! of temperature

dependent mass spectrometry

5 L
STUDENTS

Davis, K.

(U. of MD)

o Synthesis of materials for high pressure phase

transformation studies

Ceramic Powder Characterization

GUEST SCIENTISTS

Domingues, L., Mr.

(Trans Tech, Inc)

o Process experimental precursor ceramic powders

and green compacts

Stewart, J., Dr.

(U. of MD)

o X-ray characterization

Zhang , Y. , Mr

.

(U. of MD)

o X-ray characterization

STUDENT

Sung, J.

(Cornell U.)

o Powder characterization and image analysis

Surface Chemistry and Bioprocesses

GUEST SCIENTISTS

Blakemore, R., Dr.

(U. of NH)

o Ferromagnetic materials, investigate Co and U

uptake, metal transformations

Bretz, M. Dr.

(U. of Md.)

o Sol-gel processing - fractal development in

silicon gels

Kelly, R., Dr.

(Johns Hopkins U.)

o Investigation into the attachment and bacterial

solubilization of metal ores for bioengineering

Matthias, C., Ms.

(U. of MD)

o Design, develop, and implement ultra trace

molecular measurement methods

52
Thayer , J . , Dr

(U = of Cincinnati)

o Investigate bio-methylation and solubilization

of metal-containing sediments and strategic ores

Tierney, E.» Ms.

(U. of MD)

o Develop and apply multi-element specific

molecular measurement methods

GRADUATE STUDENT

Trout , T. , Mr

(U. of MD)

o Metals bioprocess monitoring,

organometallic photochemistry

RESEARCH ASSOCIATES

Degnan , T . , Dr

(Mobil Oil)

o Fossil fuel processing

Eng, G. Prof.

(U of DC)

o Theoretical and experimental applications of

molecular topology for predicting chemical

reactivity

Structural Science aed Chemistry

GUEST SCIENTISTS

Craig, C., Mr.

(DOD)

o Creep studies of various ceramic materials

Frase, K., Dr.

(IBM)

o Collaboration on small angle neutron scattering

and ceramic powder synthesis, and

characterization, and SANS

Miller, P., Mr. o Pressure dependence of the spectra of high

(Naval Surface Weapon Ctr) energy materials

Ostertag, C., Dr. o Collaborative research in ceramic processing

(U. of CA, Santa Barbara)

Ritter, A., Mr.

(Martin Marietta Lab)

o Processing of ceramic composites

Tewary, V., Dr.

(Ohio State)

o Calculating grain-boundary structures and

energies in ceramic materials

53
Vandiver, P., Dr.

(Smithsonian Conserv.

Analytical Lab)

o Phase equilibria and corrosion studies of

multicomponent ceramic systems

Vaudin , M. , Dr

.

(Cornell, U.)

o Microscopy and diffraction of ceramic interfaces

Winzer, S. Dr.

(Martin Marietta Lab)

o Ceramic processing of composites

54
OUTPUTS AND INTERACTIONS

SELECTED RECENT PUBLICATIONS

Mechanical Properties Group

Cook, R. F.; Lawn, B. R.; Fairbanks, C. J. Microstructure-strength

properties in ceramics: I. Effect of crack size on toughness. J. of

Amer. Ceram. Soc. (U.S.) 68: 604-615; 1985.

Cook, R. F. ; Lawn, B. R. ; Fairbanks, C. F. Microstructive-strength

properties in ceramics II, fatigue relations. J. Am. Ceram. Soc. 68

(11): 616-623; 1985.

Lawn, B. R. Interfacial forces and the fundamental nature of brittle

cracks. Appl. Phys. Lett. 47 (8): 809-11; 1985.

Wiederhorn, S. M. ; Hockey, B. J.; Krause, Jr, R. F. ; Jakus, K. Creep

and fracture of a vitreous-bonded aluminum oxide. J. Mater. Sci.,

810-24; 1986.

Glass and Composites Group

Birnbaum, G. ; White, G. S. ; Vest, C. M. Laser generated and detected

ultrasound and holographic methods, in pressure vessel and piping

technology 1985-A decade of progress. Sundararajan, C. R. ed, ASME,

661-669; 1985.

Cook, R. F.; Freiman, S. W. ; Baker, T. L. Effect of microstructure on reliability predicitons for glass ceramics. Mat. Sci. and Eng. 77:199;

1986.

Freiman, S. W. ; Chuck, L. ; Mecholsky, J. J.; Shelleman, D. L.;

Storz, L. J. Fracture mechanisms in lead zirconate titanate ceramics.

Fracture Mechanics of Ceramics, 7-8; 1986.

Pella, P. A.; Newbury, D. E. ; Steel, E. B.; Blackburn, D. H.

Development of National Bureau of Standards thin glass films for x-ray

fluorescence spectrometry . Anal. Chem. 58: 1133; 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, submitted to

J. Am. Ceram. Soc., 1986.

Swanson, P. L. A fracture mechanics and non-destructive evaluation

investigation of the subcritical-fracture process in rock, in Fracture

Mechanics of Ceramics, v. 8. Bradt, R. C. ; Evans, E. G. ; Hasselman, D. P. H. ; Lange, F. F. , eds. Plenum Press. 299-318; 1986.

White, G. S. ; Greenspan, D. C. ; Freiman, S. W. Corrosion and crack

growth in 33 percent Na2 0-67 percent S10 2 and 33 percent

Lio0-67 percent S102 glasses. J. Amer. Ceram. Soc. 69 (1): 38-43;

1986.

55
Tribology Group

Clark, D. B. ; Klaus, E. E. ; Hsu, S. M. The role of iron and copper in

the oxidation degradation of lubricating oils. J. Lubrication

Engineering. 41(5): 280-287; 1985.

Hsu, S. M. Lubricants, chapter in Encyclopedia of materials science

and engineering. Bever, M. , ed. New York, NY: Pergamon Press, 1985.

Hsu, S. M. ; Ku, C. S. ; Pei, P. Oxidation mechanisms of lubricant.

Presented at the ASTM Oxidation Symposium; 1983 December; Miami, FL;

in press.

Hsu, S. M. ; Pei, P.; Ku, C. S. ; Lin, R. S.; Hsu, S. T. Mechanisms of

additive effectiveness. Additives for lubricants and operational

fluids, Fifth International Colloquium, Germany. 14-16; 1986.

Ku, C. S.; Klaus, E. E. ; Hsu, S. M. A study of additive response in a series of re-refined base oils typical of current commercial practice.

Proceedings of congress International de tribologie, Elsevier, 1985.

Munro, R. G. Temperature considerations in the study of surfaces using

a four-ball wear apparatus. J. Appl. Phys. 57: 4950; 1985.

Pei, P.; Hsu, S. M. ; Preparative liquid chromatographic method for the

characterization of minor constituents of lubricating base oils, in

press.

Optical Properties Group

Feldman, A.; Farabaugh, E. N. ; Haller, W. K. ; Sanders, D. M.

Stempniak, R. A. Modifying structure and properties of optical films

by coevaporation. J. Vac. Sci. Tech.; in press.

Feldman, A. Photoelastic properties of optical materials, in

Proceedings of the SPIE; in press.

Feldman, A.; Kahn, A. H. Landau diamagnetism from the coherent states

of an electron in a uniform magnetic field. Phys. Rev. B1 : 4585; 1970;

reproduced in Coherent States Applications in Physics and Mathamatical

Physics, Klander, J. R., ed. ; Bo-Sture Skagerstam (World Scientific

Publishing, Singapore, 1985) p. 583.

Feldman, A.; Farabaugh, E. N. ; Stempniak, R. A. Self-consistent

dependence of porosity and refractive index on composition in

co-evaporated films. Laser Damage in Optical Materials, Boulder, Co,

1985; in press.

Greeninger, M. F. ; Lawn, B. ; Farabaugh, E. N. ; Wachtman, Jr., J. B. Residual stress measurements in sputtered coating on brittle

substrates by identation fracture. J. Am. Ceram. Soc.; in press.

56
High Temperature Chemistry Group

Bonnell, D. W. ; Schenck, P. K. ; Hastie, J. W. Laser vaporization mass

spectrometry. Nucl. Instr. & Methods in Phys. Res. B. Beam Interaction

with Materials and Atoms; in press.

Burton, B. P.; Davidson, P. M. Order-disorder and phase separation in

the systems Fe20o-FeTI03, CaCOo-MgCO^ adn CaMgSi 206-NaAlSi205. Proc.

14th General Meeting of the International Mineralogical Association,

1986.

Cook, L. P.; Plante, E. R. Survey of alternate stored chemical energy

reactions. NBSIR 85-3282; 1985.

Davies, P. K. ; Roth, R. S. Defect intergrowths in barium

polytitanates: -1 Ba2Ti 9°20* Solid State Chem. ; in press.

Hastie, J. W. ; Ondik, H. M.; Cook, L. P. The NBS-American Ceramic

Society Database for Ceramic Phase Diagrams, CODATA Bulletin, 58: 101

1985.

Hastie, J. W. ; Bonnell, D. W. A predictive thermodynamic model of

oxide and halide glass phase-equilibria. J. Non-Crystalline Solids; 84

(1986) 151-158.

Millet, J. M. ; Parker, H. S.; Roth, R. S. Synthesis and unit cell

determination of Ba^v^O-^ and low and high temperature Ba3?40i3. J.

Am. Ceram. Soc. 69 15): C103-C105; 1986.

Murphy, D. W. ; Cava, R. J.; Rhyne, K.; Santoro, A.; Zahurak, S. M.;

Dye, J. L.; Roth, R. S. Structural aspects of insertion reactions of

the pyrochlore, KNbWOg. Solid State Ionics 18, 19: 799-801; 1986.

Ondik, H. M. Construction materials for coal conversion—performance

and properties data. NBS Special Publication 642; Supplement 2; 1985.

Plante, E. R.; Hastie, J. W. Vaporization and phase equilibria of

simulated radionuclides. NBSIR 86-3348; 1986.

Rathnamma, D. V.; Bonnell, D. W. Contaminated fuel combustion and

material degradation life prediction model. Proceedings of the Third

Corrosion Resistant Materials Conference on High Temp. Alloys for Gas

Turbines and Other Applications, Belgium; 1986.

Roth, R. S.; Ettlinger, L. D.; Parker, H. S. Phase equilibria and

crystal chemistry in the ternary system Ba0-Ti02 -Nb 205 : Part II. New

Barium poly-tritanates with \5 raole% Nb 2

0ej. J. Solid State Chem.; in

press.

Schenck, P. K. ; Dennis, J. R. Computer graphics for ceramic phase

diagrams. CODATA Bulletin (Proc. 10th Int. Conf., Ottawa); in press.

Messina, C. G. ; Clevinger, M. A.; Cook, L. P.; Roth, R. S. Phase

diagrams for ceramists-corapilation of chemical systems and

bibliography for Volumes VI and VII. J. Am. Ceram. Soc.; 1986.

57
Structural Chemistry Group

Block, S.; Piermarini, G. J.; Hockey, B. J.; Lawn, B. R.; Munro, R. Go

High pressure transformation toughening: a case study on zirconia. J.

Am. Ceram. Soc. 69(4): 1986.

Bean, V. E. ; Aklmoto, S. ; Bell, P. M. ; Block, S. j Holzapfel, W. B.

;

Manghnani, M. H. ; Nicol, M. F. ; Stishov, S. M. Another step toward an international practical pressure scale 2nd AIRAPT IPPS task group

report. Physica 139-140B; 1986.

Mauer, F. A.; Munro, R. G. ; Piermarini, G. J. ; Block, S.;

Dandkar, D. P. Compression studies of a nickel-based superalloy,

MAR-M200 and of MijAl. J. Appl. Phys. 58(10): 3727; 1985.

Munro, R. G. ; Block, S. ; Piermarini, G. J.; Holzapfel, W. B. Model

lineshape analysis for the ruby R-lines, J. Appl. Phys. 56: 165;

1985.

Ceramic Powder Characterization Group

Dragoo, A. L. ; Robbins, C. R. ; Hsu, S. M. A critical assessment of

requirements for ceramic powder characterization. Proc. Conf. Ceram.

Powder Sci. Techno1. ; Am. Ceram. Soc.; 1986.

Jones, M. P.; Blessing, G. V.; Robbins, C. R. Dry-coupled ultrasonic

elasticity measurements of sintered ceramics and their green states.

Evaluation; 44(7): 859-62; 1986.

McMurdie, H. F. ; Morris, M. C. ; Evans, E. H. ; Paretzkin, B.;

Wong-Ng, W. ; Hubbard, G. R. Methods of producting x-ray diffracton

powdr patterns. Powder Diffracton; 1(1): 40-43; 1986.

Morris, M. C. ; McMurdie, H. F. ; Evans, E. H. ; Paretzkin, B.;

Parker, H. S. ; Wong-Ng, W. ; Gladhill, D. M. ; Hubbard, C. R. Standard

x-ray diffraction powder patterns, section 21 -data for 92 substances.

NBS Monograph 25, Section 21. National Bureau of Standards; 1985.

Robbins, C. R. ; Coblenz, W. ; Jones, M. P. Nondestructive evaluation of

green state ceramics. NBSIR 85-3187. National Bureau of Standards.

Surface Chemistry and Bioprocesses Group

Baldi, F. ; Olson, G. J. ; Brinckraan, F. E. Mercury transformations by

heterotropic bacteria isolated from cinnabar and other metal sulfide

deposits in Italy. Geomicrobiol 5: 1986; in press.

Blair, W. R. ; Olson, G. J. ; Brinckraan, F. E. ; Paule, R. C. ; Becker,

D. A. An international butyltin measurement methods intercompariosn:

sample preparation and results of analyses. NBSIR 86-3321; 56; 1986.

58
Brinckman, F. E. ; Bernhard, M. The importance of chemical speciation

in environmental processes; Dahlem Konferenzen. Berlin, Heidelberg,

New York; Springer-Verlag. 1986; in press.

Craig, P. J.; Brinckman, F. E. Occurrence and pathways of

organometallic compounds in the environment - general considerations,

in organometallic compounds in the environment. Craig, P. J. ed.,

Longman House, London; 1-64; 1986.

Matthias, C; Bellama, J. M. ; Olson, G. J. ; Brinckman, F. E. A

comprehensive method for the determination of aquatic butyltin and

butylemethyltin species at ultra-trace levels using simultaneous

hydridization/extraction with GC-FPD. Environ. Sci. Technol. 20:

609-615; 1986.

Olson, G. J.; Kelly, R. M. Microbial metals transformations:

Biotechnological applications and potential. Biotechnol. Prog. 2:

1-16; 1986.

Olson, G. J. ; Brinckman, F. E. Inorganic materials biotechnology: A

new industrial measurement challenge. J. Res. NBS 91: 1986; in press.

Olson, G. J.; Brinckman, F. E. Bioprocessing of coal: A review. Fuel;

1986; in press.

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

Characterization of organometallic polymers by size-exclusion

chromatography on preconditioned columns. J. Chromatog. 351: 475-487;

1986.

Valkirs, A. 0.; Seligman, P. F. ; Olson, G. J. ; Brinckman, F. E.

Matthias, C. L. and Bellama, J. M. Di- and tributyltin species in

marine and estuarine waters: interlaboratory comparison of two

ultratrace analytical methods employing hydridization and atomic

absorption or flame photometric detection. The Analyst; 1986; in

press.

Structure Science Group

Blendell, J. E. ; Handwerker, C. A. Effect of chemical composition on

the sintering of ceramics. J. Crystal Growth; 75(1): 138-60; 1986.

Blendell, J. E. ; Handwerker, C. A. Diffusion induced interface

migration in ceramics. Ceramic Microstructures ; 1986; in press.

Coyle, T. W. ; Guyot, M. H. ; Jamet, J. F. Mechanical behavior of a ralcrocracked ceramic composite. Ceram. Eng. Sci. Proc. ; 7(7-8); 1986.

Kaysser, W. A.; Sprissler, M. ; Handwerker, C. A.; Blendell, J. E. The

effect of a liquid phase on the morphology of grain growth in alumina.

J. Amer. Ceramic Soc. ; 1986; in press.

59
Krause, R. F. Jr. Compressive strength and creep behavior of a magnesium chromite refractory. Ceram. Eng. & Sci. Froc.; 7: 220-228;

1986.

Wiederhorn, S. M. ; Hockey, B. J. ; Krause, R. F. Jr.; Jaqkus, K. Creep

and fracture of a vitreous-bonded aluminum oxide. J. Matl. Sci.; 21;

810-824; 1986.

Wiederhorn, S. M. ; Chuck, L. ; Fuller, E. R. Jr.; Tighe, N. J. Creep

rupture of siliconized silicon carbide. Proc. of International

Conference on Tailoring Multiphase and Composite ceramics.

Pennsylvania State University; 1985.

Wiederhorn, S. M. ; Fuller, E. R. Jr. Design criteria for high

temperature structural applications. Proc. of 2nd International

Symposium on Ceramic Materials and Components for Engines,

Lubeck-Travemunde , West Germany; 1986.

Ceramic Chemistry Group

Berk, N. F. ; Hardman-Rhyne, K. A. The phase shift and multiple

scattering in small angle neutron scattering: application to beam

broadening for ceramics. Physcia; 136B: 218-222; 1986.

Hardman-Rhyne, K. A.; Berk, N. F. Character of alumina powder using

multiple small angle neutron scattering II; experiment. J. Appl.

Cryst. 18; 473-479; 1985.

Hardman-Rhyne, K. A.; Frase, K. G. ; Berk, N. F. Application of

multiple small angle neutron scattering to studies of ceramic

processing. Physcia; 136B: 223-225; 1986.

Hardman-Rhyne, K. A.; Berk, N. F. Ceramic material characterization

using small angle neutron scattering techniques. n Materials

Characterization for Systems Performance and Reliability," eds.

McCauley, J. W. ; Weiss, V. Plenum Press, New York; 257-269; 1986.

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

synthesis and characterization of phases in the barium-titanium oxide

system. J. Amer. Ceram. Soc. 69; 155; 1986.

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

powders for structural and electronics applications. "Science of

Ceramic Chemical Processing," Hench, L. L. ; Ulrich, D. R. eds., John

Wiley and Sons, New York; p. 497; 1986.

60
SELECTED TECHNICAL/PROFESSIONAL COMMITTEE LEADERSHIP

American Ceramic Society

Glass Division

S. W. Freiraan, Chairman

Committee on Glass Standards Classification and

Nonmenclature

M. J. Cellarosi, Chairman

Editorial Committee'

S. Wiederhorn, Subchairman

Basic Science Division

Editorial Committee

B . R. Lawn, Chairman

A. L. Dragoo, Subchairman

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

American Society for Metals

Energy Division Fuel Manufacturing Committee

S. J. Dapkunas, Subcommittee Chairman

Journal of Materials for Energy Systems

S. J. Dapkunas, Associate Editor

American Society for Testing and Materials

Cl 4: Glass and Glass Products

M. J. Cellarosi, Chairman

Cl 4.01: 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

S. M. Hsu, Chairman

C. S. Ku, Member

E29: Particle Size Measurement

E29.01: Advanced Ceramics, Organizational Meeting

M. J. Cellarosi

E48: Biotechnology

E48.03.07: Bioleaching of Ores

G. J. Olson, Task Group Chairman

61
American Society of Lubrication Engineers

Annual Meeting Program Committee

S. M. Hsu, Secretary

Committee on Wear

S. M. Hsu, Chairman

COMAT Subcommittee on Ceramics

S. M. Hsu, Member

Department of Energy

Materials Review Board for Nuclear Waste

H. P. R. Frederikse, Member

Gordon Research Conference on Tribology

S. M. Hsu, Vice Chairman

Gordon Research Conference on Solid State Studies in Ceramics

B. R. Lawn, Chairman

High Temperature Science Editorial Advisory Board

J. W, Hastie

Interagency Coordinating Committee on Ceramics

S. M. Hsu, Member

International Energy Agency

Task II - International Standards

Assignment I I “0-1 Powder Characterization Working Group

A. L. Dragoo, Member

International Commission for Optics

U. S. National Committee

B. Steiner, Chairman

International Union of Crystallography (lUCr)

Commission on Crystallographic Studies at Controlled

Pressures and Temperatures

G. J. Piermarini, Chairman

International Union of Pure and Applied Chemistry

Commission II“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

62
National Aeronautics and Space Administration

High Temperature Advisory Committee

D. W. Bonnell, Member

Oak Ridge National Laboratory

High Temperature Materials Laboratory Advisory Committee

S. M. Wiederhorn, Chairman

Off-Road Machinery Technology Steering Committee, Wear Task Group

S. M. Hsu, Member

Optical Society of America

1985 Annual Meeting Local Arrangements Committee

B. Steiner, Chairman

63
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 of this interaction.

INDUSTRIAL

1 . 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.

2. American Ceramic Society

The High Temperature Chemistry Group interacts with the Ceramics

Industry, through the Joint NBS/ACerS Phase Diagrams for Ceramists

Program. The ceramics industry provides information to NBS on phase

diagram needs and priorities through their participation in

ACerS-NBS Committees and through direct Interactions (visits) between

industrial and NBS management and technical personnel. The industry

is also funding a Ceramic Society program for Research Associateships

to expand the NBS Data Center on ceramic phase diagrams. The Ceramic

Society publishes and disseminates the Data Center outputs which have

included five hard-cover volumes containing 6500 evaluated phase

diagrams, and which in the future will also include on-line computer

services to industry.

3. American Iron and Steel Institute

The High Temperature Chemistry Group interacts closely with the U.S.

steel industry through participation in the AISI national Task A

committee (Ore to Steel Conversion), and technical collaboration with

various steel industry R and D personnel. A preliminary

thermochemical model for steel slag-refractory phase equilibria has

already been provided to Inland Steel.

4. 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 phosphorus, silicon, and sulfur removal.

64
5. AT&T Bell Laboratories

Research on the crystallographic characterization of ionic ceramic

conductors is being carried out in a collaborative program between

R. Jo Cava and D. W. Murphy of Bell Laboratories and A. Santoro

(Reactor Division) and R. S. Roth. Lithium inserted oxides are prepared at Bell Labs and characterized at NBS using the neutron

diffraction total profile (Rietveld) analysis. The neutron diffraction data and analysis techniques uniquely locates the position of

the lithium ion in the structure. Current emphasis of the joint work

is on alkali niobium-tungsten-vanandium oxide phases having the

pyrochlore type structure.

6c ARCO Chemical Co. - Dr. James F. Rhodes

Microstructural and structural characterization of ceramic matrix

composites correlating mechanical properties to microstructural

properties and to processing conditions.

7. Atlantic Mining Company

The Surface Chemistry and Bioprocesses Group is carrying on a research collaboration with AMC to characterize biological processes

potentially useful for recovery of precious and strategic metals from

certain major domestic deposits, of low grade pyritic ores. These

ores are not amendable to conventional processing due to matrix

effects and low grade nature of the deposits. In addition to

selective bioextraction of noble metals, platinum and gold for

example, new bioreactor designs are being evaluated for improving

iron processing.

8. AVX Corporation

S. W. Freiman and T. L. Baker 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. These are subsequently tested at NBS.

9. Battelle Memorial Institute

B. Steiner has worked closely with Battelle Memorial Institute in

identifying areas for close technical collaboration in support of a multiclient program that Battelle is assembling to develop

electrooptic technology for optical communications. Initial research

has begun in collaboration with the Center for Analytical Chemistry

in the analysis of single crystals of lithium niobate. Parallel

synchrotron topographic studies will be initiated shortly.

65
10. Bundesanstalt fur Mater ialprufung, Berlin W„ Germany

NBS/BAM Symposium on Materials Research and Testing: Ceramic

Materials

11. Crystal Technology, Inc.

B. Steiner and the Synchrotron Group of the Metallurgy Division have

collaborated with Crystal Technology on monochromatic topographic

examination of specially grown lithium niobate single crystals during

the first two weeks of dedicated x-ray ring operation at the National

Synchrotron Light Source. Crystals grown under various conditions

display highly growth-dependent defects and strains. Such defects

can affect the fabrication of complex communications and computing

devices made from these crystals. Correlation of the topographic

information with parametric variation in the crystal growth process

will help to separate those defects associated with the initial

crystal growth from those associated with subsequent diffusion to

form waveguides in the crystal.

12. Dupont Corporation

Cooperation between Ceramic Chemistry Group and industrial

laboratories (DuPont, DOW) using SANS to characterize powder

agglomeration in A100H and ZnO.

13. Georgia Tech Research Institute - Dr. Thomas Starr

Microstructural and structural characterization of ceramic matrix

composites correlating mechanical properties to microstructural

properties and to processing conditions.

14. Institute for Paper Chemistry

NBS researchers in the High Temperature Chemistry program have an ongoing interaction with the Institute for Paper Chemistry to develop

a process model for the reprocessing of spent inorganic liquors in

the production of paper. The institute is planning for Research

Associates to work at NBS. NBS has provided the Institute for a preliminary computer model and thermodynamic data base to model the

spent liquor reprocessing.

15. Max Planck Ins ti tut, Stuttgart, W. Germany

Joint work with Wolfgang Kaysser on sintering of ceramics and

diffusion induced boundary migration in ceramics and metals.

66
16. Naval Research Laboratory

Cooperative research between R. P. Ingel of the Naval Research

Laboratory and T. W. Coyle is performed concerning studies of

transformation and toughening mechanisms in Zr02 containing

ceramics.

17c Norton Co.

Cooperative research involving C. A. Willkens and N. Corbin of Norton

Co. with T. W. Coyle has begun on the characterization of the

mechanical performance of ceramic matrix fiber composites.

18. Oak Ridge National Laboratory - Drs. D. P. Stinton, T. M. Besmann and

A. J. Caputo.

Microstructural and structural characterization of ceramic matrix

composites correlating mechanical properties to microstructural

properties and to processing conditions.

19. Stauffer Chemical Company

Chemists from Stauffer Chemical Company made an extended visit to Dr.

J. J. Ritter of the Ceramic Chemistry Group to learn hands-on

procedures for generating fine metal oxide powders from metal

alkoxides. Both flask precipitation and flow-reactor precipitation

techniques were addressed.

20. VAMAS

The Tribology Group are participating in the international wear test

standardization project. Results of the first round-robin study have

been submitted and recommendation for improved procedures are being

prepared.

JOINT INDUSTRIES/UNIVERSITIES

1. AT&T Bell Laboratories, Trans Tech Division of Alpha Industries,

University of Pennsylvania and Arizona State University

A joint program on dielectric ceramics having important microwave

applications is being carried out by R. S. Roth, J. J. Ritter and

J. Blendell in association with R. J. Cava, H. O'Bryan (Bell Labs),

T. Negas (Alpha Industries), P. Davies (U. of Pennsylvania) using

electron microscope facilities at NBS and Arizona State Univ. and

with A. Olsen (Univ. of Oslo, Norway). Powders of barium

poly-titanates (pure and doped) are synthesized from alkoxide

precursors, conditioned, compacted and densifled at NBS with phase

equilibria and crystal chemistry determined at each processing step.

Characterization of microwave properties (dielectric constant, Q,

TCK, etc.,) is performed on NBS prepared powders and compacts by the

67
Industrial organizations. The University groups investigate the

materials using high resolution electron microscopy lattice imaging

techniques, correlating observed and calculated lattice image defects

with the dielectric and thermodynamic properties. On the basis of

collorative studies, the composition of the phase previously thought

to be BapNduTi-j Q02 g

has been shown to be Ba^Nd^TigOgy and a new product Is being marketed with improved properties for microwave

ceramic filter devices.

2.

General Electric and Rice University

NBS participates in a joint program with NASA for materials

processing in space. D. W. Bonnell (High Temperature Processes

Group) plans, supervises, and participates in experiments jointly

with personnel from GE and Rice University at the King of Prussia

laboratory (PA). These experiments involve use of a state-of-the-art

facility designed by Dr. Bonnell for levitation melting of tungsten

and other refractory metals coupled with drop calorimetry. The

results, in addition to providing basic thermodynamic information

indicate the limitations of ground-based versus space experiments.

UNIVERSITIES

1 Alfred University

Materials for instrument line shape calibration in x-ray diffraction

are being investigated jointly by C. Hubbard and R. Snyder (Alfred).

2. Johns Hopkins Unviversity

Robert Kelly of the Chemical Engineering Department and G. J. Olson

and F. E. Brinckman are conducting joint research on microbial

attachment to and solubilization of strategic metal ores characterized by non-destructive surface analysis techniques

including epifluorescence microscopy and FTIR. Olson is guest

lecturer in Chemical Engineering Department.

3. University of Alabama at Huntsville

A. Feldman and E. N. Farabaugh are collaborating with Dr. Karl

Guenther of the University of Alabama in studying the relationship

between processing, structure and properties of thin optical films.

The research will aid in the development of optical films with

increased stability and greater reproducibility

.

4. Massachusetts Institute of Technology (MIT)

Joint work with R. Coble (MIT), C. Handwerker (Metallurgy Division),

J. Blendell, K. Rhyne, and K. Frase (now at IBM's Watson Research

Center), involves the characterization of flaws (pores) in alumina

ceramics, by SANS and conventional microstructural techniques.

68
prepared at MIT and analyzed at NBS with the goal of correlating pore

size distributions with SANS data; an important result will be the

effect on pore size distribution caused by polishing and etching.

5. Northwestern University

Joint research involves lubrication modeling between S. Hsu 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.

6. Pennsylvania State University

The Phase Diagrams for Ceramists Data Center has an ongoing

contractual/collaborative interaction with K. Spear of the Materials

Science Department. He is developing the mathematical basis and

computer software for including NBS developed solution models into

phase diagram optimization/prediction codes. At the present time,

existing computer codes for phase diagram modeling, developed for

relatively simple alloy and molten salt systems, are not applicable

to the more complex ceramic systems, e.g., oxides. This technical

advance is necessary to the successful implementation of the

NBS/ACerS five year development program for a computerized ceramic

phase diagram data base.

The Tribology Group has several joint research projects with the

Department of Chemical Engineering and the Materials Research

Laboratory at PSU. The principal collaborators are S. Hsu, R. Munro,

and R. Gates of NBS and Prof. E. Klaus, Prof. L. Duda,

Prof. S. Naidu, D. Deckman, and J. Yellets of PSU. The research

projects include fundamental studies 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.

7. Princeton University

A. Feldman is collaborating with Dr. Philippe Fauchet of Princeton

University in measuring the phonon spectrum of thin optical films by means of Raman Spectroscopy. The experiments are expected to

identify the crystalline and amorphous phases present in optical

films, many of which are metastable. The research will aid in

developing an understanding of the relationship between processing

and structure which, in turn, will lead to more stable optical

films.

69
8. Rensselaer Polytechnic Institute

G. J. Olson and F. E. Brinckman are collaborating with Professor

Henry L. Ehrlich on mechanisms of silver ore solubilization and

resistance in metal ore processing bacteria.

9. Rice University

D. W. Bonnell interacts with J. L. Margrave of the Chemistry

Department at Rice University for the purpose of developing (and

applying) state-of-the-art levitation calorimetric techniques. These

techniques are needed for the determination of basic thermodynamic

quantities of refractory materials (e.g., W, Ta, carbides) in their

solid and liquid states. The collaborative effort is sponsored by

the NASA Materials Processing in Space Program, and General Electric

is a third member of this Government-University-Industry team.

10. Rutgers University

Joint work with J. Blum (Rutgers) and J. Blendell involves production

of seeded sol-gel glasses to be used in studies of phase controlled

crystallization at NBS.

11. University of California, Lawrence Livermore National Laboratory

Joint work with M. Weber (LLNL) and D. Blackburn and W. Haller

involves the luminescent behavior of various elements in glass

matrices. Matrix composition and processing conditions affect such

parameters as emission wavelength, band width, life time and quantum

yield which are of importance to glass lasers and optical frequency

convertors. Oxide and non-iron-oxide glasses with emitting elements

are developed at NBS and characterized for glass forming and element

loading capability. LLNL measures optical parameters, and the

results are correlated to glass composition. The goal of this work

is to improve the understanding of luminescence and may lead to novel

types of lasers.

In another joint work between NBS and LLNL, W. Haller collaborated

with T. Bernat, D. Miller and other members of LLNL in the

development of high pore volume aerogels. Aerogels of this type are used to study equation of state behavior under extreme conditions.

12. University of Cincinnati

Scientific collaboration with Prof. John S. Thayer on molecular

mechanisms of metal solubilization and transformation by biogenic

metabolites is being pursued.

70
13« University of Illinois

Steven Danyluk and Dae-Soon Lim of the Department of Civil

Engineering, Mechanics, and Metallurgy are conducting joint research

with S. M. Hsu and R. G. Munro of NBS . The project centers on an investigation of the fundamental mechanisms of friction, wear, and

surface damage in tribological applications of advanced ceramics.

14. Drexel University

The Glass and Composite Group is conducting a joint program with

Dr. M. J. Koczak of Drexel University on the fracture behavior of

ceramic matrix composites.

15. University of Maryland

Members of the Surface Chemistry and Bioprocesses Group are

collaborating with Prof. Michael Bellama and his doctoral students on biological and chemical transformations of organometallic materials

in environmental situations. Brinckman is adjunct professor in the

Chemistry Department.

C. Hubbard an A. Dragoo are participating in a collaboration with

J. Stewart and Y. Zhang, of the University of Maryland, on the

development of measurement an analysis methods for the determination

o grain size and residual strain by x-ray diffraction. Samples of

ultrafine grained MgO and ZrC^ have been obtained. The study is

expected to lead to a new Standard Reference Material.

16. University of Minnesota

Cooperative research is underway between S. Hsu and Prof. Ramalingam

on ceramic coating and coating evaluation for advanced technological

concepts

17. University of New Hampshire

The Surface Chemistry and Bioprocesses Group is collaborating

with Prof. 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.

18. University of Siena, Italy

G. J. Olson and F. E. Brinckman are collaborating with

Dr. Franco Baldi on microbiological leaching of metal orea.

71
19. University of Southern California

B. Steiner and the Synchrotron Group of the Metallurgy Division have

collaborated on monochromatic topographic examination of bismuth

silicon oxide crystals during the first two weeks of dedicated x-ray

ring operation at the National Synchrotron Light Source. These

crystals display highly growth-dependent defects and strains

associated with the detailed character of the crystal growth. Such

defects can affect the performance of signal processing devices made

from such crystals. Correlation of the topographic information with

parametric variation in the crystal growth process will help to

identify those aspects of growth that most critically affect device

performance.

20. University of Tennessee Space Research Institute (UTSI)

UTSI functions are primarily of an industrial R & D nature. Their

interaction with NBS has been long standing and revolves around their

development of coal fired MHD systems and their need for NBS basic

data and models of the MHD slag behavior. UTSI provides

(E. Plante) with slag samples from their pilot plant tests, and

NBS carries out basic vaporization and phase equilibria

measurements on these samples. The results are used by UTSI and also

by J. Hastie and D. Bonnell to develop predictive models of slag

thermochemistry under actual MHD use conditions. NBS recently

completed development of a highly successful model, which is now in

use by Lloyd Crawford of UTSI. This model can predict the

vaporization, seed retention, and phase equilibria behavior of

complex MHD slags containing oxides of Na, K, Ca, Mg, Al, Si, and

Fe.

21 . Tsinghua University

Prof. Fu-Xing Wang is conducting research with S. M. Hsu and

R. S. Gates of NBS concerning wear mechanisms of ceramic pairs.

22. State University of New York at Stony Brook: M.I.T.: U. of Maryland

P. Davidson couples her phase diagram modeling research with various

university groups. These include, phase equilibrium experiments

among olivine and pyroxene solid solutions in the CMFS system are

being conducted in collaboration with D. H. Lindsley at S.U.N.Y.; a model for CMFS pyroxene crystallization from silicate liquids is

being developed in collaboration with T. L. Grove at MIT; and

modeling of crystal - liquid fractionation in basaltic liquids is

being performed in collaboration with R. Nielsen at the University of

Maryland.

72
23. Virginia Polytechnic Institute and State University

Cooperative research between Prof. Larry Taylor (VPI). P. Pei, and

K. Jewett investigates surface reaction product analysis under

wearing conditions.

24. Uppsala University

Prof. Olof Vingsbo is collaborating with S. M. Hsu in a project

designed to identify the future critical issues in the tribology of

ceramic materials.

73
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 71

4

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 731 LI Borosilicate Glass Thermal Expansion 731 L2

Borosilicate Glass Thermal Expansion 731 L3

Cadmium Vapor Pressure 746

Chrlorine in Base Oil 1 81

8

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) 81

A

Glass Sand (Low Iron) 1 65

A

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

74
Liquids Refractive Index 1823

Low Boron Glass Composition 92

Lube Oil Oxidation Test Kit 1817

Lube Oxidation Catalysts 8500

Lubricant Oxidation Research Test Kit 8500a

MNF

2 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(A)

Silver Vapor Pressure 748

Soda Lime Flat Glass Composition S620

Soda Lime Float Composition 1830

Soda Lime Glass Viscosity 710

Soda Lime Sheet Composition 1 83

Sulfur in Base Oil 1819

Toluene 5 ML 21 1C

Tungsten Thermal Expansion 737

75

APPENDIX

CERAMICS DIVISION ORGANIZATION

Division Office Telephone Number: 301*975*6119

Division Chief: Stephen M. Hsu

Division Staff: Mario Cellarosi

S. J. Dapkunas

Camden Hubbard

Properties and Performance Groups

Mechanical Properties

Sheldon Wiederhorn, 975-5772

Glass and Composites

Stephen Freiman, 975-5761

Tribology

Ronald Munro, 975-3671

Optical Materials

Albert Feldman, 975-5740

Structure and Stability Groups

High Temperature Chemistry

John Hastie, 975-5754

Structural Chemistry

Stanley Block, 975-5733

Ceramic Powder Characterization

Alan Dragoo, 975-5785

Surface Chemistry and Bioprocesses

Frederick Brinckman, 975*5737

Processing Groups

Structural Science

Edwin Fuller, 975*5795

Ceramic Chemistry

Kay Hardman-Rhyne , 975“ 6 103

U.S.

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MBS-H4A iwev. 2-«C) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions

)

1. PUBLICATION OR

REPORT NO.

NBSIR 86-3485

2. Performing Organ. Report No. 3. Publication Date*

NOVEMBER 1986

4. TITLE AND SUBTITLE

Ceramics Division - Technical Activities 1986

5. AUTHOR(S)

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

National Bureau of Standards

Department of Commerce

Gaithersburg, MD. 20899

7. Contract/Grant No.

S. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

NBS - Ceramics Division 420

Bldg. 223, Rau A258

Gaithersburg, MD 20899

10. SUPPLEMENTARY NOTES

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information . If document includes a significant

bibliography or literature survey, mention it here)

Current programs of Ceramics Division are reviewed.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper narrfes; and seporote key words by semicolons)

Composites; glass; mechanical properties; optical materials; powder characterization;

thermodynamics; tribology.

13. AVAILABILITY

I XI Unlimited

|

[ For Official Distribution. Do Not Release to NTIS

I I Order From Superintendent of Documents. U.S. Government Printing Office. Washington. 0 C

20402.

14. NO. OF

PRINTED PAGES

90

15. Price

Order From National Technical Information Service (NTIS), Springfield, VA. 22161 $11.95

U SCOMM-OC 9043-0*0

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