5A01铝合金高温压缩流变行为

High temperature rheologic behavior of 5A01 aluminum alloy

采用Gleeble-1500热模拟机高温压缩试验,研究5A01铝合金在应变速率为0.01～1s-1、变形温度为350～450℃条件下的流变行为,并利用光学显微镜分析合金在不同压缩条件下的组织形貌特征。结果表明:应变速率和变形温度的变化强烈影响合金流变应力的大小,流变应力随变形温度升高而降低,随应变速率提高而增大。采用双曲正弦形式ARRHENIUS的关系来描述5A01铝合金高温压缩变形时的流变应力行为,获得的材料常数A、α、n和Q分别为0.06831s-1、0.0094MPa-1、2.7089和161.14kJ/mol;在应变速率为0.01s-1及变形温度低于400℃条件下变形时,5A01铝合金组织为纤维组织,而当变形温度升高到450℃时,再结晶程度很高,出现大量等轴晶。

The rheologic behavior of 5A01 aluminum alloy over the strain rate range 0.01-1s^-1 and the temperature range of 350℃ to 450℃ has been studied on Gleeble-1500 hot simulator. The microstructures of the alloy were analysed with optical microscope. The experimental results show that the theologic stress characteristic exists during hot compressive deformation of 5A01 aluminum alloy in the range of experiments. It has been found that the rheology stress is controlled by both strain rate and deforming temperature, the rheologic stress decreases with the increasing of deforming temperature, while increases with the increasing of strain rate. The rheologic stress of 5A01 alloy during high temperature deformation can be expressed by ARRHENIUS function, and the values of A, a, n and Q are 0.068 31 s^-1. 0.009 4 MP^-1, 2.708 9, 161.14 kJ/mol, respectively. When the strain rate is 0.01 s^-1 and the test temperature is less than 400℃, the microstructure of the 5A01 alloy exhibits fibrous tissues. When the deformation temperature is up to 450℃, the degree of recrystallization is high and a great number of equiaxed grains are appeared.