The effects of detwinning on the mechanical properties of AZ31B magnesium alloy with different strain rates at 423 K

In order to investigate the effects of detwinning on the mechanical property of AZ31 extruded magnesium alloy at different strain rates, tensile tests were conducted on samples which had been subjected to pre-compression to 3% along the extrusion direction, with strain rates ranging from 10−1 s−1 to 10−4 s−1 at 423 K. The results show that the strength decreases by decreasing the strain rate both on the as-received and on the pre-compressed specimens. Yield strength of pre-compressed alloy decreased comparing with as-received specimens in the whole strain rate range. Fracture elongation of undeformed specimens increased as the strain rate decreased. However, in pre-compressed materials it decreased when the strain rate ranged from 10−2 s−1 to 10−4 s−1. Changes in mechanical properties were mainly related to the softening orientation induced by the twins. Detwinning occurred during the inverse tensile deformation in the pre-compressed AZ31 alloy. Due to detwinning, DXR was delayed.