利用Gleeble-1500型热模拟试验机对含钪铝锌镁锆高强可焊铝合金进行热压缩试验, 研究了该合金在热变形过程中的流变应力; 在此基础上, 基于动态材料模型以及PRASAD失稳判据, 建立了合金的热变形加工图, 并得出了合金的最佳热加工工艺参数。结果表明: 试验合金的高温流变应力-应变曲线主要以动态回复和动态再结晶软化机制为特征, 其流变行为可以用双曲正弦形式的本构方程来描述, 其变形激活能为150.25 kJ·mol-1; 该合金适宜采用变形温度为360~400 ℃、应变速率为0.001~0.003 s-1的热加工工艺。

The thermal compression test for high-strength weldable Al-Zn-Mg-Zr alloy containing Sc was carried on Gleeble-1500 thermal simulator, the flow stress of the alloy during thermal deformation was studied, and the processing map of the tested alloy was established based on dynamic material model and PRASAD instability criterion and the optimal thermal working process parameters of the alloy was obtained.. The results show that the characteristic of high-temperature flow stress-strain curve of the tested alloy were mainly softening mechanism of dynamic recovery and dynamic recrystallization, the flow behavior could be described by a constitutive equation in hyperbolic sine function, and the deformation activation energy was 150.25 kJ·mol-1. The suitable thermal working process of the alloy was as follow: the deformation temperature was 360-400 ℃ and the strain rate was 0.001-0.003 s-1.