Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-25T01:34:21.766Z Has data issue: false hasContentIssue false

X-Ray Analysis of Fatigue Softening in Cold Worked Copper

Published online by Cambridge University Press:  06 March 2019

Roy G. Baggerly
Affiliation:
The Boeing Co., Materials Research Unit, Commercial Airplane Division, Seattle, Washington (Now at Univ. of Washington, Seattle, Washington)
Regis M. N. Pelloux
Affiliation:
The Boeing Co., Solid State Physics Laboratory, Boeing Scientific Research Laboratories, Seattle, Washington
Get access

Abstract

The recovery and recrystallization of cold rolled copper during reverse bending fatigue at room temperature has been studied with x-ray diffraction, optical microscopy and transmission electron microscopy techniques. Recovery of x-ray line breadth was recorded as a function of number of cycles at all strain amplitudes investigated. Recrystallization was observed to take place only at small strain amplitudes (life of 106 to 107 cycles). The rate of nucleation of the recrystallized grains increases with increasing strain amplitude and is a linear function of the number of cycles. The formation and growth of the grains was confined to regions near the surface of the specimen. Since comparable thermal recovery occurs at approximately 435°F it is concluded that the dynamic generation and migration of numerous point defects during fatigue is responsible for the room temperature recrystallization.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1968

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Kenyon, J. N., “The Reverting of Hard Drawn Copper to Soft Condition Under Variable Stress,” Proc. ASTM 50, 10731084, 1950.Google Scholar
2. Polakowski, W. H. and Palchoudhuri, A., “Softening of Certain Cold-Worked Metals Under the Action of Fatigue Loads,” Proc. ASTM 54, 701706, 1954.Google Scholar
3. Ham, R. K. and Broom, T., “The Mechanism of Fatigue Softening,” Phil. Mag. 7, 95103, 1962.Google Scholar
4. Feltner, C. E. and Laird, C., Cyclic Stress Strain Response of FCC Metals and Alloys I. Phenomenological Experiments, II. Dislocation Structures and Mechanisms,” Acta Met. 15, 16211654, 1967.Google Scholar
5. Baggerly, R. G., Pelloux, R. M. N., Flanagan, W. F., “X-Ray Analysis of Fatigue Damage in Copper,” in J. B. Newkirk and G. R. Mailett, Editors, Advances in X-Ray Analysis, Vol. 10, Plenum Press, New York, 1967, 328341.Google Scholar
6. Segall, R. L., Partridge, P. G., Hirsch, P. B., “The Dislocation Distribution in Face-Centered Cubic Metals After Fatigue,” Phil. Mag. 6, 14931513, 1961.Google Scholar
7. Segall, R. L., “Lattice Defects in Fatigued Metals,” in G. Thomas and J. Washburn, Editors, Electron Microscopy and Strength of Crystals, Interscience Pub., New York, 1963, 515.Google Scholar
8. Pratt, J. E., “Dislocation Substructure In Strain Cycled Copper as Influenced by Temperature,” Acta Met., 15, 319328, 1967.Google Scholar
9. Kemsley, D. S., “The Behavior of Cold Worked Copper in Fatigue,” J. Inst. Met. 87, 1015, 1958-59.Google Scholar
10. Hayes, G. A. and Shyne, J. C., “Ultrasonic Enhancement of Grain Growth in Copper,” Phil. Mag. 17, 859863, 1968.Google Scholar
11. Hayes, G. A. and Shyne, J. C., “The Influence of Ultrasonic Energy on Kinetic Processes in Solids,’ to be published in Trans, of I.E.E.E.Google Scholar
12. Hayes, G. A. and Shyne, J. G., “The Influence of Ultrasound on the Kinetics of Recrystallization in Copper,” to be published in Met. Soc. Trans, of AIME.Google Scholar