Multiaxial yield behavior of 1100 aluminum following various magnitudes of prestrain
We have found that there are several regimes of yield and flow behavior for 1100 aluminum. At strain levels below those which form shear bands, small-scale yield behavior, as reflected by a 5 x 10/sup -6/ offset yield criterion, is governed by the developing dislocation cell substructure. The yield locus is distorted and translated in the direction of the applied stress. This is because the cell structure knows the directional history of deformation. If a large offset yield criterion is used to evaluate behavior the yield locus is quite different. It is distorted very little and essentially does not translate. What distortions occur match those predicted by a texture based polycrystal plasticity theory. In short, large scale yielding is only a function of texture not microstructure. After grain scale shear bands form, (at a von Mises effective strain of approximately 0.5 for aluminum in rolling), texture alone no longer controls large offset strain yielding. These shear bands, which possibly form due to the developing texture and relaxed constraints on deformation, have a specific orientation, which produces anisotropies in plastic flow independent of texture.
- Research Organization:
- Los Alamos National Lab., NM (USA); Stanford Univ., CA (USA). Dept. of Materials Science and Engineering; Metz Univ., 57 (France). Faculte des Sciences
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6789124
- Report Number(s):
- LA-UR-84-1887; CONF-840746-2; ON: DE84013904
- Country of Publication:
- United States
- Language:
- English
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