基于应力修正的2195铝锂合金本构模型及热加工性能  

Constitutive model and hot workability of 2195 Al-Li alloy based on stress correction

作　　者：赵一帆 吴文科 何国爱[1,2,3] 王强 ZHAO Yifan;WU Wenke;HE Guoai;WANG Qiang(Light Alloy Research Institute,Central South University,Changsha 410083,China;State Key Laboratory of High Performance Complex Manufacturing,Central South University,Changsha 410083,China;Hunan Inno China Advanced Materials Co.,Ltd.,Yueyang 414000,Hunan,China)

机构地区：[1]中南大学轻合金研究院,长沙410083 [2]中南大学高性能复杂制造国家重点实验室,长沙410083 [3]湖南中创空天新材料股份有限公司,湖南岳阳414000

出　　处：《航空材料学报》2021年第5期51-59,共9页Journal of Aeronautical Materials

基　　金：国家自然科学基金(51901247);中南大学研究生自主探索创新项目(1053320184392)。

摘　　要：针对退火后的2195铝锂合金在变形温度为400~490℃、应变速率为0.01~10 s^(−1)条件下进行等温热压缩实验,对获得的真应力应变曲线进行摩擦力和温升效应的修正,并基于修正后的真应力真应变建立材料的本构关系。结果表明:实验值和预测值的相关系数R为0.99584,平均绝对误差(AARE)为3.698%,表明所建立的本构模型能很好地预测2195铝锂合金在不同变形参数下的流动应力值;基于修正后应力应变数据,通过将流变失稳图(传统热加工图)(conventional hot processing map,CHP)与变形激活能值Q耦合,建立了激活能加工(activation energy processing,AEP)图,优化出合金的热加工窗口为:应变速率<0.4 s^(−1),温度475~490℃。The isothermal compression tests of 2195 Al-Li alloy annealed at 400-490℃and strain rate 0.01-10s^(−1) were carried out.The true stress-strain curve obtained from the experiment was modified by friction force and temperature rise effects,and the constitutive relationship was established based on the modified true stress-strain curve.The results show that the correlation coefficient R is 0.99584,and the mean absolute error(AARE)is only 3.698%,which indicates that the constitutive model can well predict the flow stress of 2195 Al-Li alloy under different deformation parameters.Furthermore,based on the modified stress-strain data,the activation energy processing diagram(AEP)is established by coupling the rheologic instability diagram(conventional hot processing map,CHP)with the activation energy value Q,and the hot-working window of the alloy is optimized as follows:the strain rate is less than 0.4 s^(−1),and the temperature is 475-490℃.The constitutive relationship and activation energy thermal processing diagram of 2195 Al-Li alloy established based on the modified stress and strain can lay a good foundation for the finite element simulation of the 2195 Al-Li alloy rheological process and the formulation of processing parameters.

关 键 词：2195铝锂合金 应力应变修正 变形行为 本构方程 激活能加工图 

分 类 号：TG146.2[一般工业技术—材料科学与工程]