应变速率对AZ31B变形镁合金力学性能的影响

Influence of strain rate on tensile properties of as-extrude AZ31B magnesium alloy

为了研究应变速率对AZ31B变形镁合金力学性能的影响,在应变速率为10-1s-1、10-2s-1、10-3s-1、10-4s-1,试验温度为室温、150℃时,对AZ31B变形镁合金进行拉伸试验,并记录抗拉强度和屈服强度,计算延伸率.通过扫描电镜观察拉伸断口形貌,结果表明,随着应变速率的提高,AZ31B变形镁合金的抗拉强度和屈服强度都随之提高,而延伸率却逐渐降低;随着温度的升高,同一应变速率下的抗拉强度和屈服强度降低,而延伸率大幅度升高.通过观察扫描断口形貌发现,合金表现为韧性断裂,且随着应变速率的降低,韧窝逐渐增多.

In order to investigate the effect of strain rate on the tensile properties of as-extrude AZ31B magnesium alloy, the tensile experiments were carried out under the strain rates of 10^-1 s^-1, 10^-2 s^-1, 10^-3 s^-1 and 10^-4 s^-1 at room temperature and 15℃, respectively. The ultimate tensile strength, yield strength and elongation were determined. In addition, the observations on the fracture surfaces were performed using SEM. The results show that the ultimate tensile strength and yield strength increase with increasing strain rate, but the elongation decreases. The ultimate tensile strength and yield strength decrease with increasing test temperature, but the elongation increases highly at the same strain rate. The failure is controlled mostly by ductile fracture. The number of dimples increases with decreasing strain rate.