DEFORMATION BANDING AND COPPER-TYPE ROLLING TEXTURES

It is shown by a crystallographic etching technique applicable to copp er 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 aver age into over 600 regions of different orientations. The influence of this important, but long ignored deformation mode, is studied by incor porating 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 fc.c. rolling texture components, namely {123}[634] or S compon ent, {112}[111] or C and {110}[112] or B. The existing models are defi cient in that they predict either C and S or B, but not their co-exist ence. The second point is that textures predicted by the existing mode ls are always too sharp compared to the experimental textures. The DB model predicts texture peaks with larger spread and hence more realist ic texture sharpness. Another feature of the model is that only two in dependent slip systems, instead of five, are required to accomodate th e imposed shape change, which agrees with experimental observation.