Grain morphology related microstructural developments in bulk deformation of 2219 aluminum alloy sheet at elevated temperature

This work focuses on the plastic deformation behavior and microstructure evolution in high temperature sheet bulk forming of 2219 aluminum alloy. Uniaxial compression tests were carried out along the normal direction (ND), transverse direction (TD) and rolling direction (RD) of an annealed rolled sheet which has brick-like grains but weak texture. Electron backscattered diffraction (EBSD) was employed to observe the microstructure after compression deformation. Experimental results show strong anisotropy in plastic flow in spite of non-prominent anisotropy in strength. Meanwhile, grain refinement mechanisms transform from geometric dynamic recrystallization (GDRX) in ND compression to discontinuous dynamic recrystallization (DDRX) with enhanced particle stimulated nucleation (PSN) effect in TD and RD compressions. Grain morphology has little effect on the plastic anisotropy. However, the heterogeneous deformation associated with the distortion of brick-like grains in compression accounts for the diverse microstructural developments to a large extent.