Retaining high strength and high elongation to fracture under dynamic compressive loading in a homogenized AZ31–Ca–Mn–Zr alloy at a temperature of 250 °C
摘要
The structural component made of lightweight magnesium alloys cannot be avoided by an external load, especially from high strain rate (HSR) compression in stringent environments under different temperatures. To this end, we have conducted the quasi-static (strain rate 0.001 s−1) and HSR compression (800–2250 s−1) and reported that twinning density is dependent on the temperature and the full potential of AZ31–Ca–Mn–Zr alloy is achieved at a temperature of 250 °C under a strain rate of 2250 s−1. In particular, the ultimate compressive strength (UCS) and elongation to fracture (EF) were continuously increased at temperatures of 150 and 250 °C compared to 25 °C. The potential reason was the increase in twinning density with an increase in the temperature, twin induced rotational dynamic recrystallization (TDRX), and a resultant complex microstructure. The other deformation mechanisms also contributed in increasing of UCS and EF, and are discussed in detail. In summary, the TDRX controls the deformation and plays a pivotal role in increasing the UCS and EF. This characteristic enabled the use of lightweight AZ31–Ca–Mn–Zr Mg alloy as a promising candidate for extreme compressive loading conditions in stringent environments, potentially at a temperature of 250 °C.