【摘要】 采用Gleeble-1500热模拟试验机进行压缩实验,研究Mg-5.3Zn-0.8Zr镁合金在变形温度为473～723K、应变速率为0.01～1.00s-1的变形行为。分析合金流变应力与应变速率、变形温度之间的关系,计算高温(573～723K)下合金变形时的应力指数和变形激活能,并采用Zener-Hollomon参数法构建该合金高温塑性变形的本构关系。研究结果表明:在实验变形条件范围内,合金的真应力-真应变曲线为动态再结晶型;在573～723K,应力指数随着变形温度升高而增加,而且增加的幅度逐渐增大,变形激活能随着变形温度和应变速率的改变而发生变化。更多还原

【Abstract】 The hot deformation behavior of a Mg-5.3Zn-0.8Zr magnesium alloy was investigated by hot compressive tests on Gleeble-1500 thermal simulation test machine at 473-723 K and at the strain rates of 0.01-1.00 s-1. The relationships of flow stress,strain rate and deformation temperature were analyzed,the stress exponent and the deformation activation energy at elevated temperatures(573-723 K) were calculated. The constitutive equation of the plastic deformation of Mg-5.3Zn-0.8Zr alloy at elevated temperatures(573-723 K) was obtained by introducing Zener-Hollomon parameter. The results show that the true stress-strain curves of the alloy have dynamic recrystallization character under the present deformation conditions; within the range from 573 K to 723 K temperature,the stress exponent increases with the increase of deformation temperature and the increment increases gradually. The deformation activation energy changes with the deformation temperature and strain rate.更多还原