Al-4.7Mg-0.7Mn-0.1Zr-0.4Er合金高温变形行为

在Gleeble 1500D热模拟仪上进行热压缩实验,研究Al-4.7Mg-0.7Mn-0.1Zr-0.4Er合金高温变形行为,变形温度为300~500℃,变形速率为0.001~10 s-1,变形后总应变量为0.7。变形温度高于400℃时,真应力-真应变曲线呈现稳态流变,在其他温度下变形真应力-真应变曲线表现为加工硬化。根据动态材料模型建立合金的加工图,在400~500℃和0.001~0.1 s-1变形时加工图上出现一个发生动态回复的峰区,相应的变形激活能为176 kJ/mol,大于纯铝的自扩散激活能,表明合金在该区域变形的机制是位错的交滑移。变形失稳区的组织特征是局部变形。

Hot deformation behavior of Al-4. 7Mg-0. 7Mn-0. 1Zr-0.4Er alloy

The hot deformation behavior of Al-4. 7Mg-0. 7Mn-0.1Zr-0. 4Er alloy was investigated. Compression tests were performed on a Gleeble 1500D thermal simulator system in the temperature range of 300-500 ℃ and strain rates of 0. 001-10 s~(-1) with a total strain of 0.7.The flow curves exhibite steady state flow behavior at temperature higher than 400℃ ,and at other temperatures the alloy is characterized by strain hardening. The processing map was created based on the dynamic materials model and it predicts that the dynamic recovery of the alloy mainly occurs in a region with temperature of 400-500℃ and stain rates of 0. 001-0.1s~(-1). The corresponding apparent activation energy estimated in the region is 176 kj/mol,which is higher than that for self-diffusion in pure aluminum,suggesting that cross-slip of dislocations is the deformation mechanism. The flow instable region reveals local deformation feature.