Metallography—A Practical Tool for Correlating the Structure and Properties of Materials

241 Pages·1974·8.053 MB·English

by  Abrams H, Maniar GN

METALLQGRAPHY- A LACITCARP
TOOL ROF GNITALERROC EHT
ERUTCURTS AND SEITREPORP
FO SLAIRETAM
A symposium
detneserp at the
Seventy-sixth Annual Meeting
AMERICAN SOCIETY FOR
TESTING AND MATERIALS
Philadelphia, Pa., 25-26 June 1973
ASTM SPECIAL TECHNICAL PUBLICATION 557
Halle Abrams dna .G N. Maniar, symposium cochairmen
82-000755-40
AMERICAN SOCIETY FOR TESTING AND MATERIALS
1916 Race Street, Philadelphia, .aP 19103
(cid:14)9 by AMERICAN SOCIETY for TESTING and MATERIALS 1974
Library of Congress Catalog Card Number: 74-77096
ETON
The Society is not responsible, as a body,
for the statements and opinions
advanced in this publication.
Printed in Tallahassee, Fla.
July 1974
Second Printing May 1981
Baltimore, Md.
droweroF
The symposium on Metallography-A Practical Tool for Correlating the
Structure and Properties of Materials, saw given at the Seventy-sixth Annual
Meeting of the American Society for Testing and Materials held in Philadel-
phia, Pa., 25-26 June 1973. Committee 4-E on Metallography sponsored the
symposium. Halle Abrams, Bethlehem Steel Corporation, and G.N. Maniar,
Carpenter Technology Corporation, presided sa symposium cochairmen.
detaleR
ASTM snoitacilbuP
Electron Beam Microanalysis, STP 506 (1972),
$3.75 (04-506000-28)
Stereology and Quantitative Metallography,
STP 504 (1972), $9.75 (04-504000-28)
Manual on Electron Metallography, STP 547 (1973),
$5.25 (04-547000-28)
stnetnoC
Introduction 1
Structure-Sensitive Properties of Materials Disclosed by a Combination
of X-Ray Topography, X-Ray Diffraction Analysis, and Electron
Microscopy Methods--SIGMUND NNAMSSIEW 4
Combination Method Based on X-Ray Divergent Beam Techniques 5
Contribution of the Back-Reflection Patterns to Precision Measure-
ments of Interplanar Spacings 6
Computation of Stress-Strain Configuration of Strained Crystal;
Applications and Limitations 7
X-Ray Line Profile Analysis. Selected Area X-Ray Topography
Based on Transmission Patterns 8
Lattice Distortions and Fracture in Brittle Crystals Disclosed by
Anomalous Transmission of X-Rays (Borrmann Effect) 10
Instrumentation of X-Ray Divergent Beam Combination Method 14
Study of Fracture Mechanism in Crystals by a Combination Method
Based on X-Ray Pendello'sung Fringes, Double-Crystal Diffract-
ometry, TEM, and MES 16
Discussion-Interplay of Component Techniques in Combination
Methods 20
Conclusions 21
X-Ray Diffraction-A Versatile, Quantitative, dna Rapid Technique of
Metallography--LEO LLEWZ 23
Specimen Preparation 24
Elemental Analysis 25
Phase Identification 29
Other Structural Characteristics 34
Conclusion 40
The Use of Hot-Stage Microscopy in the Study of Phase Transforma-
tions-a. .L ,TTIFMARB .A .O ,RETOCSNEB J. .R ,KCIRTAPLIK DNA .A
a. REDRAM 43
Experimental Technique 43
Heating Stage 44
Applications 54
Examination of Materials by Coherent Light Techniques-R. .J ,REFEAHCS
J. .A ,TTEGDOLB DNA .M .E NAMSKCILG 71
Coherence 72
Optical Transforms 72
Holography 75
Optical Correlation 84
Summary 84
The Electron Microprobe sa a cihpargollateM Tool-J. .I NIETSDLOG 86
Electron Microprobe 87
Elemental Analysis 94
Scanning Electron Probe 103
Characterization of Phases 108
EMP Analysis of Phases 115
Extension of Instrument Capability 120
Transmission Electron Microscopy in slairetaM Research-M. .G .H SLLEW
DNA .J .M SONEPAC 137
Instrument Design Improvements 141
New Observation Techniques 141
Use of TEM in Structure-Property Relationships 144
High Voltage Electron Metallography-Achievements dna Prospects-
A. SZIRMAE AND R. M. FISHER 169
Characteristics of High Voltage Microscopy 171
Applications 184
Future Developments 196
Microstructure Approach to Property Optimization in Wrought Super-
alloys--D. .R AKYZUM DNA .G .N RAINAM 198
Alloys 199
Primary Manufacturing Steps 201
Phases in Wrought Superalloys and Metallographic Techniques 203
Microstructures and Properties 205
Recent Developments 206
Micrograin Processing 206
Structure Control Heat Treating 208
Minigrain Processing 210
Thermomechanical Processing 212
Summary 217
Phase Separation as a Technique for the Characterization of Superalloys
--0. .H EGEIRK 220
Specific Techniques for Phase Separation 221
Analysis of Separated Phases 225
Application of Phase Separation to Metallurgical Studies 227
Summary 233
STP557-EB/Jul. 1974

noitcudortnI
In the last several years the characterization of materials by metallographic
techniques has been paralleled by a remarkable improvement in material
capabilities. The ability to measure and characterize those material parameters
that provide improved mechanical and physical properties has led directly to
the development of new and better materials. Well known metallographic
techniques such as hot-stage microscopy, transmission electron microscopy
(TEM), and X-ray analysis, as well as the more recent techniques of scanning
electron microscopy (SEM) and automatic quantitative metallography have
provided the means to measure, characterize, statistically interpret, and, final-
ly, predict the properties of materials.
The successful correlation of the structure and properties of materials,
whether on a theoretical or empirical level, has been one of the primary forces
in the current materials revolution. Accordingly, the objective of this sympo-
sium was to present both review and original papers that demonstrated, on a
practical level, the application of an expanded range of metallographic tech-
niques to the measurement, characterization, statistical interpretation, and
prediction of the behavior of materials.
The papers presented have been prepared by authorities in their fields and
include almost all phases of modern metallographic techniques. The opening
session dealt with electron optical metallography covering the areas of electron
microprobe analysis, SEM, and high voltage and conventional electron metal-
lography. The second session covered hot-stage microscopy, microhardness
techniques, and the new laser techniques of evaluating metallographic struc-
tures. The final session included a complete review of the techniques and
applications of X-ray metallography and two application papers in the field of
superalloys.
This special technical publication includes all the papers presented at the
symposium, with the exception of the SEN and microhardness papers, which
are not included due to publication deadlines.
Professor Weissman's paper is an excellent and concise summary of the
X-ray metallographic techniques that he and his colleagues have developed to
a high degree of sophistication over the past several years. In his paper, he
describes various applications where combination X-ray methods are used to
correlate lattice defects with structure-sensitive properties. In particular, his
description of the use of X-ray Pendell6sung fringes to analyze the distribu-
thgirypoC (cid:14)9 4791 by MTSA Intemational www.astm.org
2 METALLOGRAPHY
tion of microplastic and elastic strains in crack propagation would be of
special interest to researchers working with low dislocation-density materials.
In contrast to the more specialized techniques discussed by Weissman, Zwell's
paper deals with practical applications of the more common X-ray metaUo-
graphic techniques such as phase identification, residual-stress analysis, and
texture determinations. The author demonstrates the usefulness of these tech-
niques in failure analysis as well as in the development of new alloys.
In their paper, Bramfitt et aL, summarize the experimental techniques used
in hot-stage light microscopy and the application of these techniques to the
study of ferrous transformations. The paper provides a description of all the
transformations occurring in low-alloy steels and includes an excellent bibliog-
raphy. Of particular merit is the authors' work on the austenite to pearlite
transformation emphasizing the advantage of in situ measurements on a single
specimen to determine pearlite-nodule growth rates and transformation kinet-
ics. Another innovative technique in light microscopy is described by Schaefer
et aL Their paper discusses the basic concepts involved in the analysis of
metallographic structures using optical transforms, holography, and other
coherent-light methods. For the materials scientists, the most useful applica-
tions of holography employ interferometry to study transient events that
occur at unpredictable locations, for example, the solidification of transparent
analogs of metals.
The following three papers relate to the use of electron optics for character-
izing and correlating the structure and properties of materials. In his paper,
Professor Goldstein discusses the resolution and types of information that can
be obtained from the various X-ray, secondary electron, and backscattered
electron signals measured in the electron microprobe. The paper demonstrates
the versatility of the microprobe as a metallurgical tool in the characterization
of phases, diffusion studies, trace-element analysis, and quantitative metallog-
raphy. The paper also contains an up-to-date and extensive bibliography. The
review paper by Wells and Capenos describes applications of TEM in materials
research. In covering selective papers from the literature, the authors provide
several practical examples of the role of TEM in the study and understanding
of materials system. The scope of applications of electron metallography has
been expanded considerably with the advent of high-voltage instruments
capable of operating at 1 MeV or more. In the area of high voltage electron
metallography, the contributions of Szirmae and Fisher are well known, and
their present paper presents a broad review of their work and a look toward
the future of high voltage electron metallography (HVEM).
The paper by Muzyka and Maniar demonstrates the application of various
metaUography methods in optimizing properties of superalloys on the basis of
a microstructural approach. The authors illustrate the value of microstructural
studies in conjunction with phase relationships in improving hot working,
heat-treat response, and the property optimization of iron and iron.nickel base
superalloys. The contribution of analytical chemistry in support of micro-
structure studies is exemplified by Kriege's paper on phase separation as a
INTRODUCTION 3
technique for the characterization of superalloys. Although the paper deals
with superalloys, the technique is equally applicable to other material systems.
These introductory comments on the papers contained in this volume
illustrate the significant role that metallography plays in the development and
characterization of materials. It was our objective in organizing this sympo-
sium to show, through both original studies and state-of-the-art reviews, how
the metaUographic disciplines within the scope of Committee E-4 on MetaUog-
raphy validate the premise that metallography is a practical tool for correlat-
ing the structure and properties of materials. We hope that this publication
has contributed to the achievement of our objective. The American Society
for Testing and Materials (ASTM) and the program chairmen wish to thank
the authors for their excellent contributions to the symposium and this
volume.
Halle Abrams
Homer Research Laboratories,
Bethlehem Steel Corp.,
Bethlehem, .aP 18015; symposium
.namriahcoc
Gunvant N. Maniar
,reganaM Research and
Development Center,
Carpenter Technology Corp.,
Reading, .aP 19603; symposium
coehairman.