Compressive Deformation Behavior of AZ31Mg Alloy Containing {10–12} Extension Twins at Different Temperature

Abstract

Influence of pre-introducing {10–12} extension twins on compressive deformation behavior of AZ31Mg alloy at different temperature was investigated. The compression tests were conducted along the normal direction of AZ31Mg alloy at room temperature, 100 °C, 200 °C and 300 °C with a strain rate of 1 × 10−3 s−1. The results indicated that the pre-introducing {10–12} extension twins strongly affected the yield strength, the peak strength and the strain hardening rate at middle-low temperature (≤ 200 °C). The twinned samples containing pre-introducing {10–12} extension twins exhibited smaller yield strength and larger peak strength than the as-received samples without {10–12} extension twins at temperature ≤ 200 °C. For the as-received samples, the strain hardening rate decreased gradually at different temperature. While for the twinned samples, the strain hardening behavior exhibited three distinct stages at temperature ≤ 200 °C. When compressing at 300 °C, the as-received and twinned samples exhibited similar compression flow curves and strain hardening rate curves. The continuous dynamic recrystallization (CDRX) was the main dynamic recrystallization (DRX) mechanism in the as-received sample when compressing at 200 °C. The twin assisted DRX besides CDRX was also initiated in the twinned sample when compressing at 200 °C. While the DRX mechanism was transformed into the discontinuous dynamic recrystallization (DDRX) in both the as-received and twinned samples when compressing at 300 °C.