Improvement of stretch formability and weakening the basal texture of Mg alloy by corrugated wide limit alignment and annealing process

Abstract

In this paper, a process of corrugated wide limit alignment (CWLA) was used to improve the stretch formability of large-dimension AZ31 Mg alloy sheets by inducing tensile twins. The effects of {10 1¯ 2} tensile twins on microstructure evolution, mechanical properties and stretch formability of AZ31 Mg alloy sheet was studied. The results indicated that the CWLA samples exhibited a weakened basal texture and a high fraction of twin boundaries due to the twinning and recrystallization behavior. After CWLA and annealing for 30min at 300 °C, the strain-hardening exponent value increased from 0.2 to 9.4, the Lankford value decreased from 2.85 to 0.37, and the Erishen value was increased by ∼95% compared to the as-received samples. The present study would provide a new insight into the development of Mg alloys having excellent stretch formability.

Keywords

• Mg sheet
• Corrugated wide limit alignment
• Tensile twins
• Recrystallization
• Stretch formability