2195铝锂合金的热变形本构模型及热加工图

Hot Deformation Constitutive Model and Processing Map of 2195 Al-Li Alloy

采用Geeble-3500型热模拟试验机对2195铝锂合金进行单道次热压缩试验,研究了该合金在360~510℃变形温度和0.001~10 s^(-1)应变速率条件下的热变形行为;根据试验获得的应力、应变数据,建立基于Zener-Hollomon模型的流变应力双曲正弦函数本构模型,并绘制相应的热加工图,获得适宜的热加工工艺。结果表明:2195铝锂合金的流变应力随应变速率的增加而提高,随变形温度的升高而降低,该合金具有正应变速率敏感性;2195铝锂合金的热变形激活能为189.392 kJ·mol^(-1);2195铝锂合金的适宜热加工工艺为变形温度在410~430℃、应变速率小于0.0147 s^(-1)以及变形温度在470~510℃、应变速率小于0.0269 s^(-1)。

The single-pass hot compression test of 2195 Al-Li alloy was carried out by Geeble-3500 thermal simulator.The hot deformation behavior under the deformation temperature of 360-510℃and strain rate of 0.001^(-1)0 s^(-1) of the alloy was studied.The constitutive model of hyperbolic sine function based on Zener-Hollomon model was established according to the stress and strain data obtained by tests,and the hot processing map was drawn to obtain the suitable hot working process.The results show that the flow stress of 2195 Al-Li alloy increased with increasing strain rate and decreased with increasing deformation temperature.The alloy had positive strain rate sensitivity.The hot deformation activation energy of 2195 Al-Li alloy was 182.392 kJ·mol^(-1).The suitable hot working process of 2195 Al-Li alloy was listed as follows:410-430℃deformation temperature,less than 0.0147 s^(-1) strain rate and 470-510℃deformation temperature,less than 0.0269 s^(-1) strain rate.