Dynamic recrystallization, texture and mechanical properties of high Mg content Al–Mg alloy deformed by high strain rate rolling
Xinyu Li, Weijun Xia, Jihua Chen, Hongge Yan, Zhenzhen Li, Bin Su, Min Song
Abstract
The Al–Mg alloy with high Mg addition (Al–9.2Mg–0.8Mn–0.2Zr-0.15Ti, in wt.%) was subjected to different passes (1, 2 and 4) of high strain rate rolling (HSRR), with the total thickness reduction of 72%, the rolling temperature of 400 °C and strain rate of 8.6 s−1. The microstructure evolution was studied by optical microscope (OM), scanning electron microscope (SEM), electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). The alloy that undergoes 2 passes of HSRR exhibits an obvious bimodal grain structure, in which the average grain sizes of the fine dynamic recrystallization (DRX) grains and the coarse non-DRX regions are 6.4 and 47.7 μm, respectively. The high strength ((507±9) MPa) and the large ductility ((24.9±1.3)%) are obtained in the alloy containing the bimodal grain distribution. The discontinuous dynamic recrystallization (DDRX) mechanism is the prominent grain refinement mechanism in the alloy subjected to 2 passes of HSRR.