Deformation banding and copper-type rolling textures

Abstract

It is shown by a crystallographic etching technique applicable to copper that deformation banding is an important deformation mode in f.c.c. metals and alloys. In a cold rolled coarse grain copper, deformation banding forms in a three dimensional manner dividing the grain on average into over 600 regions of different orientations. The influence of this important, but long ignored deformation mode, is studied by incorporating it into the Taylor model. The predicted textures from the new model are better than those from other existing models in mainly two respects. Firstly, the DB model predicts the co-existence of the three major f.c.c. rolling texture components, namely {123}〈634〉 or S component, >112>〈111〉 or C and >110>〈112〉 or {f}B{/f}. The existing models are deficient in that they predict either C and S or B, but not their co-existence. The second point is that textures predicted by the existing models are always too sharp compared to the experimental textures. The DB model predicts texture peaks with larger spread and hence more realistic texture sharpness. Another feature of the model is that only two independent slip systems, instead of five, are required to accomodate the imposed shape change, which agrees with experimental observation.