Microstructure and Texture Evolution of GWS841 Magnesium Alloy During Hot Extrusion.

In this experiment, the solid solution GWS841 magnesium alloy was deformed by hot extrusion at 500 °C. EBSD was used to analyze the evolution of microstructure and texture under different degrees of deformation. The results showed that the average grain size decreased from 75.8 μm to 3.2 μm and the DRX fraction increased from 5.6 ± 1.5% (position A) to 84.5 ± 3.8% (position D). The fraction of low-angle grain boundaries (LAGB) first increased and then decreased with the increase in deformation ratio. Three main nucleation mechanisms operate during hot extrusion: twin-induced dynamic recrystallization, continuous dynamic recrystallization and discontinuous dynamic recrystallization, with continuous dynamic recrystallization as the dominant nucleation mechanism. A fiber texture was formed during the extrusion process, which originated from the non-DRXed grains and the intensity of the fiber texture first increased and then decreased with the increase in the deformation ratio. The DRXed grains formed the fiber texture.