6069铝合金的热变形行为和加工图

Hot deformation behavior and processing map of 6069 aluminum alloy

采用Gleeble-1500热模拟实验机在温度为300～450℃,应变速率为0.01～10 s?1条件下对6069铝合金进行热压缩实验,研究该合金的热变形行为及热加工特征,建立热变形本构方程和加工图。结果表明,6069铝合金热变形过程中的流变行为可用双曲正弦模型来描述,在实验条件下的平均变形激活能为289.36 kJ/mol。真应变为0.7的加工图表明合金在高温变形时存在2个安全加工区域,即变形温度为300～350℃、应变速率为1～10 s?1的区域和变形温度为380～450℃、应变速率为0.01～0.3 s?1的区域。适合加工的条件是变形温度为350℃,应变速率0.01 s?1。

The thermal compaction testing on 6069 aluminum alloy was carried out in the temperature range of 300-450 ℃ and the strain rate range of 0.01-10 s-1 on Gleeble-1500 hot-simulation machine.The hot deformation behavior and hot workability of the alloy were studied and constitutive equation and processing map were established.The results show that the flow behavior of 6069 aluminum alloy can be described by the hyperbolic sine function and the activation energy is about 289.36 kJ/mol in the present experimental condition.The processing map established at the true strain of 0.7 shows that there are two safe deformation zones of hot deformation for the alloy,including the zone in the deformation temperature range of 300-350 ℃ and the strain rate range of 1-10 s-1,and other zone in the deformation temperature range of 380-450 ℃ and strain rate range of 0.01-0.3 s-1.The deformation temperature of 350 ℃ and deformation rate of 0.01 s-1 are the best hot deformation condition.