Ultrafine-Grain Ceramics

400 Pages·1970·11.756 MB·English

by  Alexis G. Pincus (auth.), John J. Burke, Norman L. Reed, Volker Weiss (eds.)

Ultrafine-Grain Ceramics
SAGAMORE ARMY MATERIALS RESEARCH
CONFERENCE PROCEEDINGS
Published by Syracuse University Press
Fundamentals of Deformation Processing
eds., Walter A. Backofen and others
(9th Proceeding)
Fatigue-An Interdisciplinary Approach
eds., John J. Burke, Norman L. Reed, and Volker Weiss
(lOth Proceeding)
Strengthening Mechanisms-Metals and Ceramics
eds., John J. Burke, Norman L. Reed, and Volker Weiss
(12th Proceeding)
Surfaces and Interfaces I
Chemical and Physical Characteristics
eds., John J. Burke, Norman L. Reed, and Volker Weiss
(13th Proceeding)
Surfaces and Interfaces II
Physical and Mechanical Properties
eds., John J. Burke, Norman L. Reed, and Volker Weiss
(14th Proceeding)
Ultrafine-Grain Ceramics
• • • • • • •
EDITORS
JOHN J. BURKE
Staff Scientist, Army Materials and
Mechanics Research Center
NORMAN L. REED
Associate Director, Army Materials and
Mechanics Research Center
VOLKER WEISS
Professor, Syracuse University
Proceedings of the 15th Sagamore Army Materials
Research Conference. Held at Sagamore Conference
Center, Raquette Lake, New York, August 20-23.
1968. Sponsored by Army Materials and Mechanics
Research Center, Watertown, Mass., in cooperation
with Syracuse University. Organized and directed by
Army Materials and Mechanics Research Center in
cooperation with Syracuse University.
SYRACUSE UNIVERSITY PRESS
Copyright © 1970
Softcover reprint of the hardcover 1st edition 1970
by Syracuse University Press
Syracuse, New York
First Edition
All Rights Reserved
Standard Book Number
8156-5026-4
Library of Congress
Catalog Card Number: 64-12568
ISBN-13: 978-1-4684-2645-8 e-ISBN-13: 978-1-4684-2643-4
DOl: 10.1007/978-1-4684-2643-4
Sagamore Conference Committee
Chairman
Norman L. Reed, Army Materials and Mechanics
Research Center
Vice Chairman
John J. Burke, Army Materials and Mechanics
Research Center
Program Director
Volker Weiss, Syracuse University
Program Coordinator
Robert J. Sell, Syracuse University
Program Committee
Irving Berman, Army Materials and Mechanics
Research Center
Capt. Stuart L. Blank, Army Materials and Mechanics
Research Center
John J. Burke, Army Materials and Mechanics
Research Center
H. M. Davis, U. S. Army Research Office
Alexis G. Pincus, lIT Research Institute
Norman L. Reed, Army Materials and Mechanics
Research Center
Richard M. Spriggs, Lehigh University
Arrangements at
Sagamore Conference Center
Richard A. Jones, Syracuse University
Foreword
The Army Materials and Mechanics Research Center has conducted the Saga
more Army Materials Research Conferences, in cooperation with the Metallurgi
cal Research Laboratories of the Department of Chemical Engineering and
Metallurgy of Syracuse University, since 1954. The purpose of the conferences
has been to gather together scientists and engineers from academic institutions,
industry, and government who are uniquely qualified to explore in depth a sub
ject of importance to the Army, the Department of Defense and the scientific
community.
Grain size and its control is a major factor governing the behavior of materi
als. Knowledge that one can obtain grain sizes in the 10 micron down to sub
micron range has established the basis for a new technology.
This volume, Ultrafine-Grain Ceramics, addresses itself to the broad areas of:
realization of fine-grain ceramics; preparation of ultrafine particle size materials;
characterization of ultrafine particles and ultrafine-grain ceramics; processing
and behavior of ultra fine-grain ceramics.
The technical advice provided by Dr. S. K. Dutta of the Army Materials and
Mechanics Research Center during the editing of this book is acknowledged.
The continued active interest and support of these conferences by Dr. E.
Scala, Director, Lt. Col. Joseph B. Mason, Commanding Officer, and J. F.
Sullivan, Deputy Technical Director, of the Army Materials and Mechanics Re
search Center is appreciated.
Sagamore Conference Committee The Editors
Raquette Lake, New York
August, 1968
Contents
SESSION I
INTRODUCTION
Norman L. Reed, Moderator
Realization of Fine-Grain Ceramics
A. G. Pincus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SESSION II
PREPARATION OF ULTRAFINE PARTICLE SIZE MATERIALS
Stuart L. Blank, Moderator
2 Fine Grinding-Size Distribution, Particle Characterization and Mechan
ical Methods
T. P. Meloy. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
3 Preparation of Ultrafine Particles of Metal Oxides
K. R. Hancock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39
SESSION III
CHARACTERIZATION OF ULTRAFINE PARTICLES AND
ULTRAFINE-GRAIN CERAMICS
Joseph A. Pask,Moderator
4 On the Problems of Characterizing Fine Powders
B. H. Kaye and M. R. Jackson. . . . . . . . . . . . . . . . . . . . . . . .. 63
5 Optimum Procedures for Determining Ultrafine-Grain Sizes
J. E. Hilliard, J. B. Cohen, and W. M. Paulson. . . . . . . . . . . . . .. 73
6 The Role of Composition in Ultrafine-Grain Ceramics
M. H. Leipold and E. R. Blosser . . . . . . . . . . . . . . . . . . . . . . .. 99
7 Microstructure of Fine-Grain Ceramics
N. J. Tighe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 109
SESSION IV
PROCESSING OF ULTRAFINE-GRAIN CERAMICS
Richard M. Spriggs, Moderator
8 Fine Particulates to Ultrafine-Grain Ceramics
T. Vasilos and W. Rhodes . . . . . . . . . . . . . . . . . . . . . . . . . . .. 137
ix
x CONTENTS
9 Solid-State Sintering
D. L. Johnson. . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 173
10 Determination of an Effective Viscosity of Powders as a Function of
Temperature
W. S. Young, S. T. Rasmussen, and I. B. Cutler ................ 185
11 Hot Forming of Ceramics
R. W. Rice ....................................... 203
12 Superplasticity in Ceramics
P. E. D. Morgan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
13 Ultrafine-Grain Ceramics from Melt Phase
J. Hurt and D. J. Viechnicki ............................ 273
SESSION V
BEHAVIOR OF ULTRAFINE-GRAIN CERAMICS
S. M. Copley, Moderator
14 Proposed Theory for the Static Fatigue Behavior of Brittle Ceramics
D. P. H. Hasselman ................................ 296
15 Crack Propagation in Polycrystalline Ceramics
S. M. Wiederhorn .................................. 317
16 Plastic Deformation in Fine-Grain Ceramics
A. H. Heuer, R. M. Cannon, and N. J. Tighe ................ 339
17 Electrical and Magnetic Behavior of Ultrafine-Grain Ceramics
A. 1. Mountvala .................................. 367
Index ............................................ 391
SESSION I
INTRODUCTION
MODERATOR: NORMAN L. REED
Army Materials and Mechanics Research Center
Watertown, Massachusetts
1. Realization of Fine-Grain Ceramics
ALEXIS G. PINCUS
IIT Research Institute
Chicago, Illinois
ABSTRACT
Grain size is but one factor in the complex microstructures of ceramics.
Ability to control or minimize unwanted phases has made feasible evaluation of
the effect of grain size on physical properties, but interpretations must also
account for other influences such as grain bonding and internal strains, surface
condition, and extrinsic flaws. Recently, attention has been focused on process
ing as the key to grain refinement. The diverse approaches within particulate,
melt, and vapor-processing will be highlighted in terms of potential for control
over grain size.
Introduction
This conference is concerned with ultra fine-grain ceramics and how to pre
pare them. * The reason for our interest is that some remarkable improvements
in various properties of practical significance appear to take place as grain sizes
grow smaller. For example, we are at a stage where tantalizing promise exists
that grain refinement will provide dramatic improvements in the strength of
monolithic ceramics. A ceiling which has existed for more than a decade in the
strength of alumina ceramics at 50,000 psi flexural is now being upgraded to
100,000 psi reproducibly, with promise of an even higher plateau. Similar dra
matic property improvements with grain refinement have been propounded for
one after another of the large variety of compositions of oxide ceramics which
have been finding unique uses: barium titanate for capacitors, ferrites for re
cording heads or memory cores, zirconia for refractoriness in oxidizing atmo
spheres, lithium aluminosilicates for thermal shock resistant materials, and so on.
But the promises have remained tantalizing because of lack of assurance that
the higher property levels can be achieved outside of the laboratory, repro
dUCibly and economically. This lack of reproducibility has been ascribed to two
factors: (1) inadequate knowledge about all the other interrelated features of
*Ultrafine grain is being arbitrarily defined as less than 10 J.I. in diameter.
3