Detwinning-related Bauschinger effect of an extruded magnesium alloy AZ31B

Highlights: • Bauschinger effect of a fiber-textured AZ31B magnesium alloy was investigated. • Bauschinger effect is sensitive to strain rate and pre-strain under the T-U-C loading mode. • Bauschinger effect shows no evident sensitivity to strain rate under the C-U-T loading mode. • Bauschinger effect is related to detwinning accompanied with stress relaxation. -- Abstract: Bauschinger effect of a fiber-textured AZ31B magnesium alloy was investigated with different pre-strains and strain rates under two loading modes: tension-unloading-reverse compression (T-U-C) and compression-unloading-reverse tension (C-U-T). Bauschinger effect was characterized and evaluated with Bauschinger Energy Parameter (BEP). The result showed that under the T-U-C loading mode, Bauschinger effect is sensitive to strain rate and pre-strain, but it shows no evident sensitivity to strain rate under the C-U-T loading mode. Detwinning accompanied with stress relaxation is responsible for Bauschinger effect, while the accumulation of dislocation induced by slip helps to reduce Bauschinger effect at high pre-strain.