Residual Stress Analysis of Textured Materials by X-Ray Diffraction Method

Abstract:

The residual stress measurement by the conventional X-ray diffraction was formulated on the assumption that a specimen from polycrystalline materials was quasi-isotropic and homogeneous, and the stress was biaxial and almost constant within the X-ray penetration depth. Therefore, it was not available to analyze the stress state of the textured materials by the conventional measurement as a general rule. In resent years, advanced methods have been proposed for the X-ray stress measurement of textured materials. In some methods, it is assumed that the X-ray elastic constant is derived from the crystallite orientation distribution function of textured materials for solving the first anisotropic problem. However, there is a nonlinear problem in the stress analysis from the measured lattice strain. In present study, the X-ray elastic constants were averaged as the expected value around the normal direction of the X-ray diffraction in a similar way. A stress analysis was proposed by differential calculus of the X-ray elastic constant in order to the avoidance of nonlinear problem. The stress analysis was applied to residual stress measurements of a titanium carbide coating film with preferred orientation and a cold-rolled steel with texture. The calculated values of the X-ray elastic constants showed the linearity on some condition for the film. The X-ray stress determination was carried out by the fitting the gradients of the measured lattice strain.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 1673-1678
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.1673
• Online since: January 2012
• Authors: Shouichi Ejiri, Toshihiko Sasaki, Yukio Hirose
• Keywords: Residual Stress, Stress Measurement, Textured Materials, X-Ray Diffraction Method

References

[1] I.C. Noyan, J.B. Cohen, Residual Stress: Measurement by Diffraction and Interpretation, Springer-Verlag, (1987).

[2] S. Nagashima, Shougousoshiki (Texture), Maruzen, (1984).

[3] A. Reuss, Berechnug der Fliessgrenze von Mischkristallen auf Grund der Plastizitätsbedingung für Einkrisalle, Z. Angew. Math. Mech. 9 (1929) 49-81.

DOI: 10.1002/zamm.19290090104

[4] H.J. Bunge, Texture Anlysis in Materials Science: Mathematical Methods, Butterworths (1982).

[5] C.M. Brakman, Residual stress in Cubic Materials with Orthorhombic or Monoclinic Specimen Symmetry: Influence of Texture on ψ Splitting and Non-linear Behavior, J. Appl. Cryst., 16 (1983) 325-340.

DOI: 10.1107/s0021889883010511

[6] M. Barral, J.L. Lebrun, J.M. Sprauel, G. Maeder, X-ray Macrostress Determination on Textured Materials; Use of the ODF for Calculating the X-ray Compliance, Mer. Trans. A, 18A (1987) 1229-1238.

DOI: 10.1007/bf02647192

[7] P.V. Houtte, L.D. Buyser, The Infuence of Crystallographic Texture on Diffraction Measurement of Residual Stress, Acta Metall. Mater. 41 (1993) 323-326.

DOI: 10.1016/0956-7151(93)90063-x