Evolution Behavior of Shear Band in Al‐0.5Mg‐0.4Si‐0.1Cu Alloy during Hot Compression Process

Abstract

To clarify the evolution behavior of shear bands in Al‐0.5Mg‐0.4Si‐0.1Cu alloy under high‐temperature conditions, isothermal compression tests are carried out under 400, 450, and 500 °C with 50% compression at a strain rate of 1 s−1. Through electron backscattered diffraction (EBSD), Schmid factors are mainly distributed between 0.395 and 0.495, making lattices easy to rotate and shear bands formed. The shear band, a local plastic deformation structure, has a significant impact on the dynamic recrystallization and preferred orientation of grains. Through the recrystallization distribution maps, subgrains absorb a large amount of dislocations, which increases the grains’ orientation difference, resulting in the formation of recrystallized grains with high‐angle grain boundaries. In addition, bulging grain boundaries promote the formation of new nuclei. The newly formed nuclei will generate and grow by absorption of dislocations, which is the feature of discontinuous dynamic recrystallization. These two phenomena are further confirmed by transmission electron microscope tests. Finally, R‐Cube textures mainly form in shear bands at 400 °C, while in the matrix, E‐textures mainly form at 400 and 450 °C, and R‐Goss textures are rotated to form at 500 °C, which is confirmed by EBSD test results.