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ASTM Selected Technical Papers
Fifty Years of Progress in Metallographic Techniques
By
Committee E-4
Committee E-4
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ISBN-10:
0-8031-6181-6
ISBN:
978-0-8031-6181-8
No. of Pages:
417
Publisher:
ASTM International
Publication date:
1968

Application of the electron microscope hot stage can provide unequivocal evidence for the nature of thermal processes. The difficulties inherent in the technique, however, have minimized its use up to the present. In particular these difficulties are: (1) the intervention of surface diffusion (not characteristic of bulk processes) due to the large surface area of thin foils, (2) the differences in mechanisms of both sheartype and diffusional processes which sometimes develop between thin foils and bulk materials, (3) the contamination of reactive materials by the environment provided by present electron microscopes, (4) the changes in contrast conditions of thin foils congruent with expansion of their lattices and with buckling due to thermal strains, and (5) the inaccuracy of measuring the temperature of the foil while being observed. Methods of circumventing these difficulties are described. Criteria for the successful application of the hot stage are established in view of these difficulties. It is concluded that the type of phenomenon best treated by means of the hot stage is one occurring on the scale of hundreds of angstroms but not greater than 0.2 μ to prevent interference by the foil surface, and repeating at intervals of the order of microns in order to increase the probability of obtaining results, particularly when using ciné techniques. Thus, very fruitful studies of continuous and discontinuous precipitation processes, ordering reactions, and recovery phenomena may be made with ease, while investigations into recrystallization or certain martensitic transformations are not likely to be successful unless extensive preliminary studies are made.

1.
Thomas
,
G.
, “
High Temperature High Resolution Microscopy
,”
American Institute for Mining, Metallurgical, and Petroleum Engineers
,
Gordon and Breach
, to be published.
2.
Watanabe
,
M.
,
Someya
,
T.
, and
Nagahama
,
Y.
, “
Temperature Rise of Specimen Due to Electron Irradiation
,”
Proceedings
, 5th International Conference Electron Microscopy,
Philadelphia
,
1962
, p. A-8.
3.
Gale
,
B.
and
Hale
,
K. F.
, “
Heating of Metallic Foils in an Electron Microscope
,”
British Journal of Applied Physics
 0508-3443, Vol.
12
,
1961
, pp. 115–117.
4.
Ling
,
J.
, “
A Method for Estimating the Temperature Distribution in an Electron Microscope Specimen
,”
British Journal of Applied Physics
 0508-3443, Vol.
16
,
1965
, pp. 501–507.
5.
Van Torne
,
L. I.
and
Thomas
,
G.
, “
Phase Transformations in Niobium Involving Interstitials
,”
Acta Melallurgica
 0001-6160, Vol.
12
,
1964
, pp. 601–615.
6.
Laufer
,
E. E.
and
Roberts
,
W. N.
, “
Dislocations and Persistent Slip Bands in Fatigued Copper
,”
Philosophical Magazine
 0031-8086, Vol.
14
,
1966
, pp. 65–78.
7.
Williamson
,
G. K.
,
Rickards
,
G. K.
, and
Cornell
,
R. M.
, “
Electron Microscope Sample Holder for Precision Annealing at Temperatures up to 3000°C Outside the Microscope
,”
Journal of Scientific Instruments
 0950-7671, Vol.
43
,
1966
, pp. 481–482.
8.
von Heimendahl
,
M.
and
Wasserman
,
G.
, “
Electronenmikroskopische Untersuchungen an Ausscheidungen einer Aluminum-Kupfer-Legierung
,”
Zeitschrift für Metallkunde
 0044-2267, Vol.
53
,
1962
, pp. 275–283.
9.
Hartman
,
R. E.
and
Hartman
,
R. S.
, 24th Annual Meeting,
Electron Microscope Society of America
,
1966
, p. 16.
10.
Heidenreich
,
R. D.
,
Fundamentals of Transmission Electron Microscopy
,
Interscience
,
New York
,
1964
.
11.
Thomas
,
G.
and
Whelan
,
M. J.
, “
Observations of Precipitation in Thin Foils of Aluminum + 4% Copper Alloy
,”
Philosophical Magazine
 0031-8086, Vol.
6
,
1961
, pp. 1103–1114.
12.
Laird
,
C.
and
Aaronson
,
H. I.
, “
Mechanisms of Formation of θ and Dissolution of θ' Precipitates in an Al-4% Cu Alloy
,”
Acta Melallurgica
 0001-6160, Vol.
14
,
1966
, pp. 171–185.
13.
Murphy
,
J. B.
, “
Interdiffusion in Dilute Aluminum-Copper Solid Solutions
,”
Acta Melallurgica
 0001-6160, Vol.
9
,
1961
, pp. 563–569.
14.
Hren
,
J. A.
and
Thomas
,
G.
, “
Direct Observations of Precipitation in Thin Foils of Al-20% Ag Alloy
,”
Transactions, American Institute for Mining, Metallurgical, and Petroleum Engineers
 0096-4778, Vol.
227
,
1963
, pp. 308–318.
15.
Silcox
,
J.
and
Whelan
,
M. I.
,
Structure and Properties of Thin Films
,
Wiley
,
New York
,
1959
, p. 164.
16.
Laird
,
C.
and
Aaronson
,
H. I.
, “
Crystallographic Complexities in the Al-Cu System
,”
Acta Melallurgica
 0001-6160, Vol.
15
,
1967
, pp. 660–662.
17.
Mader
,
S. R.
, “
Precipitation in Thin Films of Fe-Au
,”
Oral Presentation, American Institute for Mining, Metallurgical, and Petroleum Engineers
, Spring Meeting,
New York
,
1966
.
18.
Hornbogen
,
E.
, “
Precipitation in Iron-based Alloys
,”
Symposium
,
Cleveland
,
American Institute for Mining, Metallurgical, and Petroleum Engineers
,
Gordon and Breach, New York
,
1963
.
19.
Derge
,
G.
,
Kommel
,
A. R.
, and
Mehl
,
R. F.
, “
Studies of the Widmanstätten Structure, IX-The Mg-Mg2 Sn and Pb-Sb Systems
,”
Transactions, American Institute of Mining, Metallurgical, and Petroleum Engineers
 0096-4778, Vol.
124
,
1937
, pp. 367–378.
20.
Pitsch
,
W.
, “
The Martensite Transformation in Thin Foils of Iron-Nitrogen Alloys
,”
Philosophical Magazine
 0031-8086, Vol.
4
,
1959
, pp. 577–584.
21.
Bailey
,
J. E.
,
Electron Microscopy and Strength of Crystals
,
Thomas
,
G.
and
Washburn
,
J.
, eds.,
Interscience
,
New York
,
1963
p. 535.
22.
Hu
,
Hsun
,
Electron Microscopy and Strength of Crystals
,
Thomas
,
G.
and
Washburn
,
J.
, eds.,
Interscience
,
New York
,
1963
, p. 564.
23.
Harris
,
J. E.
and
Masters
,
B. C
, “
The Annealing of Faulted Loops in Magnesium and Zinc
,”
Proceedings, Royal Society
, Vol.
A292
,
1966
, pp. 240–263.
24.
Segall
,
R. L.
,
Partridge
,
P. G.
, and
Hirsch
,
P. B.
, “
The Dislocation Distribution in Face-centered Cubic Metals after Fatigue
,”
Philosophical Magazine
 0031-8086, Vol.
6
,
1961
, pp. 1493–1513.
25.
Gallagher
,
P. C. J.
and
Valdré
,
U.
, Vth Italian Conference of Electron Microscopy,
Bologna
,
1965
.
26.
Ericsson
,
T.
, “
The Temperature and Concentration Dependence of the Stacking Fault Energy in the Co-Ni System
,”
Acta Melallurgica
 0001-6160, Vol.
14
,
1966
, pp. 853–865.
27.
Whelan
,
M. J.
, “
Dislocation Interactions in Face-centred Cubic Metals
,”
Proceedings, Royal Society
, Vol.
A249
,
1958
, pp. 114–137.
28.
Jössang
,
T.
 et al
, “
On the Determination of Stacking Fault Energies from Extended Dislocation Node Measurements
,”
Acta Melallurgica
 0001-6160, Vol.
13
,
1965
, pp. 279–291.
29.
Brown
,
L. M.
, “
The Self-Stress of Dislocations and the Shape of Extended Nodes
,”
Philosophical Magazine
 0031-8086, Vol.
10
,
1964
, pp. 441–466.
30.
Brown
,
L. M.
and
Thölen
,
A. R.
, Discussion, “
Dislocations in Solids
,”
Faraday Society
,
Göttingen
,
1964
, p. 35.
31.
Aaronson
,
H. I.
,
Symposium on the Decomposition of Austenite by Diffusional Processes
,
Zackay
,
V. F.
, and
Aaronson
,
H. I.
, eds.,
1963
, p. 387.
32.
Laird
,
C.
and
Aaronson
,
H. I.
, “
The Dislocation Structures of the Broad Faces of Widmanstätten γ Plates in an Al-15% Ag Alloy
,”
Acta Melallurgica
 0001-6160, Vol.
15
,
1967
, pp. 73–103.
33.
Laird
,
C.
and
Aaronson
,
H. I.
, “
Structures and Migration Kinetics of α:θ' Boundaries in Al-4% Cu: Part I. Interfacial Structures. Part II. Kinetics of Migration
,”
Ford Motor Co.
, Technical Reports, Nos. SL-67-45 and SL-67-52,
1967
.
34.
Garwood
,
R. D.
and
Davies
,
A. L.
, “
The Effect of Structural Imperfections on the Age-hardening of Aluminum-Zinc Alloys
,”
Journal of the Institute of Metals
 0020-2975, Vol.
88
,
1959
, pp. 311–317.
35.
Clark
,
J. B.
, “
High Temperature High Resolution Microscopy
,”
American Institute of Mining, Metallurgical, and Petroleum Engineers
,
Gordon and Breach
, to be published.
36.
Nemoto
,
M.
and
Koda
,
S.
, “
Direct Observation of Transformation from the θ' to the θ Phase in the Precipitation of an Aluminum-Copper Alloy
,”
Nippon Kinzoku Gakkai-si
 0021-4876, Vol.
27
,
1963
, pp. 599–604.
37.
Hashimoto
,
H.
 et al
, 24th Annual Meeting,
Electron Microscope Society of America
,
San Francisco
,
1966
, P-13.
38.
Bigelow
,
W. C.
,
Brockway
,
L. O.
, and
Rowe
,
A. P.
, 24th Annual Meeting,
Electron Microscope Society of America
,
San Francisco
,
1966
, P-5.
39.
Natesh
,
G.
and
Ansell
,
G. S.
Oxide Growth in an Al-Al2O3 SAP-type Alloy by Hot Stage Transmission Electron Microscopy
,”
Acta Melallurgica
 0001-6160, Vol.
14
,
1966
, pp. 1735–1756.
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