超高强Al-Zn-Mg-Cu-Zr合金的热变形行为

Hot Deformation Behavior of Al-Zn-Mg-Cu-Zr Alloy with Super-High Strength

采用圆柱试样在Gleeble 15 0 0热模拟机上进行恒温和恒速压缩变形实验 ,变形温度范围为 3 5 0～ 45 0℃ ,应变速率范围为 0 .0 0 1～ 0 .1s- 1 。研究了 70 5 5铝合金在高温塑性变形过程中流变应力的变化规律 ,确定了合金的变形激活能Q和应力指数n。结果表明 ,流变应力随变形温度的升高而降低 ,随应变速率的提高而增大。可用应力 应变速率方程来描述 70 5 5铝合金高温压缩变形时的热变形行为。这种合金在 3 5 0～ 45

The mechanical behavior of 7055 aluminum alloy during high temperature plastic deformation was studied by isothermal compression of cylindrical specimen using gleeble 1500 at constant temperature and constant strain rate. The deformation temperature ranges from 350 to 450 ℃, strain rate from 0.001 to 0.1 s -1 . The thermal deformation activation energy Q and stress exponent n were calculated, and the hot deformation micro structure were observed. The results show that the flow stress is controlled by both strain rate and deforming temperature, the flow stress decreases with the increase of deforming temperature, while increases with the increase of strain rate. The hot deformation behavior of 7055 aluminum alloy compressed under high temperature can be represented by stress strain rate equation. Dynamic recovery structure together with a few recrystallizaion structure are observed after hot deformed at 350～450 ℃.