Enhancing compressive mechanical properties of rolled AZ31 Mg alloy plates by pre-compression

Abstract

{10–12} extension twins were pre-introduced in the hot-rolled AZ31 Mg alloy plates by pre-compression at room temperature (RT) along the transverse direction (TD). Pre-introduced {10–12} extension twins substantially improved the yield strength of AZ31 Mg alloy plates and did not deteriorate the compression ratio. Especially at RT, 100 °C and 200 °C, the pre-compressed samples containing {10–12} extension twins exhibited much larger yield strength (122 MPa vs. 66 MPa, 121 MPa vs. 64 MPa and 118 MPa vs. 63 MPa) than the initial samples. The pre-compressed sample showed more obvious compression flow softening phenomenon than the initial sample at 200 °C, which was attributed to the dynamic recrystallization (DRX) process accelerated by pre-introduced {10–12} extension twins. When compressing at 300 °C, the compression flow curves of the initial and pre-compressed samples tended to coincidence, which was because the discontinuous dynamic recrystallization (DDRX) was the controlling mechanism in both kinds of the samples and the effect of pre-introduced {10–12} extension twins was vanished.