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Lattice Strain Measurements on Deformed FCC Metals

Published online by Cambridge University Press:  06 March 2019

Eckard Macherauch
Eckard Macherauch*
Affiliation:
Max-Planck-Institut für Metallforschung, Stuttgart, Germany
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Abstract

In this work experiments have been undertaken to determine the type of residual stresses of plastically deformed polycrystals of aluminum, copper, and nickel which cause a shift of the X-ray interference lines. In order to get accurate stress values, the lattice strain distribution has been measured in special planes of the deformed specimens, using the sin2 ψ technique. The surface stresses were determined as a function of the macroscopic plastic strain of cylindrical specimens. With increasing strain, the residual surface stress component parallel to the direction of deformation increases. The stresses observed are compressive ones after tension and tensile ones after compression.

The changes in the residual lattice strain distributions which arise on progressive thinning of the plastically deformed specimens have been measured. From the stress values determined in each new surface layer, the stress distribution originally present in the uodestroyed specimen was calculated. Tensile stresses in the interior of the specimens are in equilibrium with compressive stresses in the surface areas. The formation of residual stresses on specimens with a work-hardened surface layer is found to be quite different from that of well-annealed samples.

The results of this work seem to show that in uniaxially deformed cylindrical specimens, residual macrostresses arise which may be a consequence of a macroscopic inhomogeneity of work-hardening between the surface layers and the interior of the polycrystals.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 9: Fourteenth Annual Conference on Applications of X-ray Analysis, August 25-27, 1965 , 1965 , pp. 103 - 114
Copyright
Copyright © International Centre for Diffraction Data 1965

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References

1. Barrett, C. S., Structure of Metals, 2nd ed., McGraw Hill, New York, 1952.Google Scholar
2. Cullity, B. D., Elements of X-Ray Diffraction, Addison-Wesley Publishing Co., Reading, Mass., 1954.Google Scholar
3. Glocker, R., Materialprüfung una Röntgemtrahlen, 4th ed., Springer-Verlag, Berlin, 1958.Google Scholar
4. Greenough, G. B., “Quantitative X-Ray Diffraction Observations on Strained Metal Aggregates,” Progr. Metal. Phys. 3: 176–219, 1952.Google Scholar
5. Vasil'ev, D. M. and Smirnov, B. I., “Certain X-Ray Diffraction Methods of Investigating Cold Worked Metals,” Usp. fis. Nauk 73: 503, 1961.Google Scholar
6. Macherauch, E., “Principles and Problems of the X-Ray Determination of Elastic Stresses,” Materialpruefüng 5: 14–25, 1963.Google Scholar
7. Hauk, V., Z. Metallk. 55: 626, 1964.Google Scholar
8. Glocker, R. and Hasenmeier, H., “X-Ray Stress Measurements on the Beginning of the Flow Process in Carbon Steels,” Z. Ver. shut. Ing. 84: 825–828, 1940.Google Scholar
9. Nishihara, T. and Taira, S., “Effect of Free Surface in the Yielding Resistance of Materials,” Mem. Fac. Eng. Kyoto Univ. 12: 90–118, 1950.Google Scholar
10. Smith, S. L. and Wood, W. A., “Internal Stress Created by Plastic Flow in Mild Steel, and Stress-Strain Curves for the Atomic Lattice of Higher C Steels,” Proc. Roy, Sec. (London) Ser. A 182: 404–414, 1944.Google Scholar
11. Vasil'ev, D. M., “Character of the Initial Stage of Plastic Deformation in Poly crystalline Metals,” Fix. Metal i Metalloved, 14: 106–113, 1962.Google Scholar
12. Greenough, G. B., “Residual Lattice Strains in Plastically Deformed Polycrystalline Metal Aggregates,” Proc. Roy. Soc. (London) Ser. A 197: 556–567, 1949.Google Scholar
13. Macherauch, E. and Millier, P., “Lattice Deformation and Residual Strains in Pure and Alloyed Aluminum Specimens after Stress Deformation,” Z. Metallk. 49: 324-331, 1958. “Influence of Wavelength in Lattice Strain X-Ray Measurements,” Z. Metallk. 51: 514–523, 1960.Google Scholar
14. Macherauch, E. and Muller, P., Z. Angeio. Phys. 13: 305, 1961.Google Scholar
15. Moore, M. G. and Evans, W. P., SAE Trans. 66: 340, 1958.Google Scholar
16. Kolb, K. and Macherauch, E., “X-Ray Studies of the Plastic Deformation of Sinter Nickel,” 53: 108–114, 1962.Google Scholar
17. Guard, R. W., “Etch Pit Method for Revealing Dislocation Sites in Nickel,” Trans. AIME 218: 573–574, 1960.Google Scholar