Roles of detwinning in strain hardening and ultimate elongation in extruded Mg–3Al–1Zn alloy

Abstract

For extruded magnesium alloy, prior compression along extrusion direction has great influences in the flow stress during subsequent tension. Detwinning plays an important role for these influences. In the present study, the effects of different prestrains on strain hardening behaviour during subsequent tension were examined in an extruded magnesium alloy AZ31. The results showed that the existence of detwinning decreased the tensile yield stress. Samples with different prestrains exhibited different strain hardening behaviour during subsequent tension. The reorientation due to detwinning had a great effect on strain hardening during tension. In addition, the effect of detwinning on ultimate elongation was investigated. The results showed that the sample with higher prestrain always has higher ultimate elongation due to the contribution of detwinning on macroscopic strain.

Keywords:

• Magnesium alloys
• Detwinning
• Strain hardening
• Plastic deformation

Acknowledgements

This work was supported by sharing fund of Chongqing University’s large scale equipment (grant no. 2012121513). The authors are also grateful to J. She and Z. Yu for their valuable assistance in various aspects of the experimental program.