Microstructure and microtexture evolution of shear bands in Al–Cu single crystal during asymmetric rolling

Abstract

Asymmetric rolling process (ASR) introduces extra shear deformation compared with conventional symmetric rolling (SR), and induces shear bands in microstructures. ASR technique has been applied to manufacture thick aluminum plate with improved mechanical properties due to the fine grains or even ultrafine-grains obtained in shear bands. Single crystal specimens of Al–Cu alloys were prepared in this work to study the microstructure and texture evolution in asymmetric rolled sheet. Microstructures of deformation bands were observed and the microtexture was analyzed through electron backscatter diffraction (EBSD). Compared with the SR process, ASR induced more homogeneous deformation and shear bands were observed in deformation area. Microstructure of shear bands depends on the initial orientations of single crystals. After single crystal with (3, −1, 9) plane orientation is processed in ASR, shear bands consist of S-type grains were formed, which have uniform size and almost the same twisting degree. But for single crystal with (−3, 0, 7) plane orientation, shear bands have various twisting degrees and grains distributed inhomogeneously. Texture of the shear bands in ASR processed specimens always rotated towards Copper component for single crystals with different orientations.