2219铝合金的平面应变压缩变形行为及本构方程  

Deformation Behavior and Constitutive Equation of 2219 Aluminum Alloy during Plane Strain Compression

作　　者：覃秋慧 刘胜胆[1,2] 唐建国 何克准[3,4] 贾桂龙 张航[3,4] QIN Qiuhui;LIU Shengdan;TANG Jianguo;HE Kezhun;JIA Guilong;ZHANG Hang(School of Materials Science and Engineering,Central South University,Changsha 410083,China;State Key Laboratory of Lightweight High-Strength Structural Materials,Changsha 410083,China;Guangxi ALNAN Aluminum Inc.,Nanning 530031,China;Guangxi Key Laboratory of Materials and Processing of Aluminum Alloys,Nanning 530031,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]轻质高强结构材料国家重点实验室,长沙410083 [3]广西南南铝加工有限公司,南宁530031 [4]广西铝合金材料与加工重点实验室,南宁530031

出　　处：《机械工程材料》2024年第12期121-130,共10页Materials For Mechanical Engineering

基　　金：广西科技重大专项项目(AA23023026)。

摘　　要：通过平面应变压缩试验获得2219铝合金在变形温度320~480℃、应变速率0.1~10 s^(-1)、最大真应变1.2条件下的压缩变形行为;基于试验得到的真应力-真应变数据和Arrhenius双曲正弦模型,分别建立峰值应力本构方程和应变补偿本构方程,获得合金的热变形激活能和应力指数,分析合金的变形机制。结果表明:在平面应变压缩过程中,合金的流变应力先迅速升高,达到峰值应力后稍有下降,最后趋于稳定;流变应力随变形温度的升高或应变速率的降低而降低。峰值应力本构方程预测的真应力与试验值的最大相对误差为4.57%;应变补偿的本构方程预测得到的真应力与试验值的平均绝对相对误差为2.62%,线性相关系数为0.9953。建立的本构方程都能够准确预测2219铝合金在平面应变压缩变形过程中的流变应力。在整个变形过程中热变形激活能范围为135.138~145.410 k J·mol^(-1),应力指数范围为5.920~6.930,表明变形时合金主要的扩散机制为晶格扩散,主要的变形机制为位错攀移。The deformation behavior of 2219 aluminum alloy was obtained by plane strain compression tests under deformation temperatures of 320-480℃,strain rates of 0.1-10 s^(-1),and a maximum true strain of 1.2.Based on the test true stress and true strain data and Arrhenius hyperbolic sine model,the peak stress constitutive equation and strain compensation constitutive equation were established,and the thermal deformation activation energy and stress exponent of the alloy were calculated.The deformation mechanism of the alloy was analysed.The results show that during plane strain compression,the flow stress of the alloy first increased rapidly,and decreased slightly after reaching the peak stress,and finally tended to be stable.The flow stress decreased with the increase of deformation temperature or the decrease of strain rate.The maximum relative error between stresses predicted by the peak stress constitutive equation and the test value was 4.57%.The average absolute relative error between the predicted true stress by strain compensation constitutive equation and the test value was 2.62%,and the linear correlation coefficient was 0.9953.The established constitutive equation both could accurately predict the flow stress of 2219 aluminum alloy during the plane strain compression deformation.During the whole deformation,the thermal deformation activation energy ranged from 135.138 k J·mol^(-1)to 145.410 k J·mol^(-1),and the stress exponent ranged from 5.920 to 6.930,indicating that the main diffusion mechanism was lattice diffusion and the main deformation mechanism was dislocation climbing.

关 键 词：2219铝合金 平面应变压缩 本构方程 热变形激活能 变形机制 

分 类 号：TG339[金属学及工艺—金属压力加工]