论文部分内容阅读
采用Gleeble1500热模拟试验机对Al-Li-Cu-Mg-Zn-Ag合金进行等温热压缩实验,研究其在变形温度范围为300~500℃,应变速率范围为0.001~10 s-1内的热变形行为。分析了合金流变曲线特征,构建该合金在真应变分别为0.1,0.3和0.5时的加工图并讨论了真应变为0.5时的安全区和失稳区组织特征。结果表明:Al-Li-Cu-Mg-Zn-Ag合金的流变曲线分为过渡变形阶段和稳态变形阶段,流变应力的数值随变形温度的升高而减小,随应变速率的增加而增大;3种真应变下的加工图显示,能量耗散因子具有相似的变化趋势,均在高温低速区达到峰值,失稳区覆盖的范围随应变量的增加而增大,当真应变为0.5时,失稳区参数为变形温度300~480℃,应变速率0.01~10.00 s-1;当真应变为0.5时,安全区以动态回复组织为主,有少量动态再结晶,失稳区组织出现了局部流变带;在变形量较小(真应变0.5)的情况下,建议Al-Li-Cu-Mg-Zn-Ag合金热加工工艺为变形温度范围410~480℃,应变速率范围0.003~0.100 s~(-1)。
The isothermal hot compression experiments of Al-Li-Cu-Mg-Zn-Ag alloy were carried out on a Gleeble1500 thermal simulator. The results show that when the deformation temperature is in the range of 300-500 ℃ and the strain rate is in the range of 0.001-10 s-1 Thermal deformation behavior. The characteristics of the rheological curve of the alloy were analyzed. The machining diagram of the alloy at true strain of 0.1, 0.3 and 0.5 was constructed and the microstructure characteristics of the safe zone and the unstability zone were discussed. The results show that the rheological curves of Al-Li-Cu-Mg-Zn-Ag alloy are divided into the transitional deformation phase and the steady deformation phase. The values of rheological stress decrease with the increase of deformation temperature. With the increase of strain rate The energy dissipation factor has a similar trend, all of them reach the peak at high temperature and low velocity, and the coverage of the unstable region increases with the increase of the strain, and when the true strain is 0.5, the parameters of instability zone are the deformation temperature of 300 ~ 480 ℃ and the strain rate of 0.01 ~ 10.00 s-1. When the true strain is 0.5, the dynamic zone is dominated by the dynamic recovery organization with a small amount of dynamic recrystallization and the instability zone appears In the case of small deformation (true strain 0.5), it is proposed that the hot-working process of Al-Li-Cu-Mg-Zn-Ag alloy is carried out in the temperature range of 410 ~ 480 ℃, strain rate range of 0.003 ~ 0.100 s ~ (-1).