7055铝合金高温塑性变形的热模拟研究
Study on Hot Deformation Simulation of 7055 Aluminum Alloy at High Temperature
李周兵, 沈 健, 闫亮明, 李俊鹏
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作者单位：北京有色金属研究总院 加工工程研究中心, 北京 100088
中文关键字：7055铝合金； 热模拟； 流变应力； 变形激活能； 动态回复
英文关键字：7055 aluminum alloy; hot deformation simulation; flow stress; deformation activation energy; dynamic recovery
中文摘要：采用Gleeble-1500D热模拟机研究了7055铝合金在应变速率为0.01、0.1和1 s-1、变形温度为300～450℃，最大真应变为0.7条件下的高温塑性变形行为，分析了合金流变应力与应变速率、变形温度之间的关系，计算了合金高温塑性变形时的变形激活能，并观察了合金变形过程中显微组织变化情况。 结果表明：合金在热变形过程中流变应力随温度的升高而减小，随应变速率的增加而增大，7055铝合金的高温塑性变形行为可以用包含Zener-Hollomon参数的流变应力方程进行描述。该合金在实验条件范围内热变形以动态回复为主要软化机制并伴随极少量的再结晶发生。
英文摘要：The plastic deformation simulation of 7055 aluminum alloy at high temperature was performed on Gleeble-1500D hot simulator with the strain rates of 0.01 , 0.1 and 1 s-1 deforming at 300 ～450 ℃ and the maximum deformation degree of 0.7. The relationship between flow stress and deformation temperature as well as strain rate was analyzed and the deformation activation energy was calculated. The variations of microstructure during hot deformation process were observed. The results show that there are various types of flow stress at different temperature and strain rate. The flow stress decreases with the increase of deforming temperature, while increases with the increase of strain rate. The deformation activation energy increases with the increase of strain rate. The hot deformation behavior of 7055 aluminum alloy compressed at high temperature can be represented by constitutive equation of Zener-Hollomon parameters. The main soften mechanism of the alloy is dynamic recovery, together with a little dynamic re-crystallizaion.