| From slip traces produced by microhardness indentation, orientation of grains in a commercial Cu-30 Zn brass has been determined before and after rolling reduction of 30% at room temperature. Different deformation structures were observed on grains, where the Schmid factor analysis shows that they depend on the number of active slip systems at rolling. When the primary slip system is unique, deformation is homogeneous, but when more than one slip system are equally active, deformation is heterogeneous; in particular, large, distinct subgrains can be formed. It was also observed that when a twin axis is parallel to the transverse direction, regions contiguous to the twin boundary rotate together, thus remaining a narrow band of twin couple after rolling. From these observations, it was concluded that slip mechanism, during the first stage of cold-rolling, may include (1) multi-directional rotations on the same grain and (2) a binding force of the twin boundary on contiguous regions. |
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