Influence of strain path on the microstructure evolution and mechanical properties in AM31 magnesium alloy sheets processed by differential speed rolling

The influence of strain path on the microstructure evolution and mechanical properties in AM31 magnesium alloys fabricated by twin roll cast (TRC) and subsequent DSR (differential speed rolling) process was investigated. The experimental results indicated that grains were significantly refined due to shear bands formed during differential speed rolling-reverse (DSR-R) process, and the microstructures of AM31 processed by DSR-R process were much more homogeneous than those of AM31 processed by differential speed rolling-normal (DSR-N) process. Compared with DSR-N process, DSR-R process produced a homogeneous microstructure with fine grains and tilted weak texture was obtained due to the formation of shear bands. Improvement of strength and ductility in AM31 magnesium alloys processed by DSR-R process was achieved by grain refinement and tilted weak basal texture. In additional to apparent advantages in energy saving, combined DSR-R and TRC process is suggested to be a potential technique of plasticity enhancement of magnesium alloys.

► A novel DSR (DSR-R) was used to fabricate AM31 magnesium alloy sheets.
► DSR-R process resulted in fine-grained microstructure with a weak basal texture.
► The tensile strength and ductility were improved by DSR-R process.