Crystal plasticity modeling of texture evolution and heterogeneity in equal channel angular pressing of aluminum single crystal

Abstract

A crystal plasticity finite element method (CPFEM) model has been developed to investigate the texture evolution and heterogeneity during equal channel angular pressing (ECAP) of an aluminum single crystal. The developed model has been validated by comparison with experimental observations. The simulation results show that the lattices rotate predominantly around the Z axis (transverse direction) during ECAP. After deformation the billet is subdivided into three matrix bands along the thickness by the Z-axis rotation. The Z-axis rotation angles within three matrix bands are about 60°, 0° and 90°, respectively. It has been found that the die geometry plays a very important role on the texture evolution and heterogeneity in ECAP. In the large strain gradient region, multi-slip can be activated and the material rotation induced by slips is negligible. The lattices must rotate to accommodate the whole material rotation required by deformation. When the strain gradient is small, the single dominant slip is the main slip mechanism. The material remains roughly at the initial orientation after deformation. There is a rigid-rotation region in the lower part of the die corner where the lattices rotate by the die angle Φ.