SUBSTRUCTURE - TEXTURE - CORRELATION IN PLASTICALLY DEFORMED METALLIC MATERIALS

A. Riedel, P. Klimanek

Orientation changes during plastic deformation of polycrystalline metallic materials are closely related to the operating deformation mechanisms as, for instance, dislocation slip, mechanical twinning, shearbanding, or also strain-induced martensite formation. Accordingly it can be expected that crystallites with different preferred orientation (texture components) have different substructures (i.e. different content of deformation-induced lattice defects) and form the fractions of a lattice-disorder statistics defined in [1,2,3]. In order to analyze the microstructural inhomogeneity resulting from the different deformation behaviour of the texture components a texture-related methodology of substructure analysis is necessary.

The present paper informs about the results of such investigations which were performed by means of X-ray line broadening analysis in connection with quantitative X-ray texture measurements. The sample materials were cold-rolled sheets of copper, $\alpha$-brass CuZn$_{30}$, and $\alpha$-iron with different thickness reduction ($\epsilon \leq 90 \%$). They were cut in such a manner [4] that only crystallites of a selected texture component {hkl} contributed to the formation of the measured reflections h = {hkl}. The evaluation of the line-broadening was carried out on the base of a treatment of the Stokes-corrected Fourier coefficients as described in [2,3,4].

In all materials the X-ray reflections due to different texture components of the rolling texture have significantly different physical line broadening and, consequently, substructure characteristics (e.g. dislocation densities). In agreement with TEM observations of other authors (cp. [4]) the results illustrate that there are strong interrelations between substructure and texture development in the plastic deformation of polycrystals. Simultaneously it becomes visible that analysis of X-ray (or neutron) diffraction line broadening is suitable for a detailed integrated substructure characterization in bulk materials with complicated sample architecture.

1. Klimanek, P. : Freiberger Forschungsheft B 265, 74 - 93. Dt. Verlag fur Grundstoffindustrie, Leipzig 1988
2. Klimanek, P. : X-Ray and Neutron Structure Analysis in Materials Science (Ed. J. Hašek), 125-137. Plenum Press, New York 1989
3. Klimanek,P.: Proc. EPDIC 1, Mat.Sci.Forum 79-82 (1991) Part 1, 73-84
4. Klimanek, P. : Proc. ICOTOM 10, Mater.Sci.Forum 157-162 (1994) 1119