7075铝合金热变形的组织演化及本构方程研究  

Microstructure evolution and constitutive equation in hot deformation of 7075 aluminum alloy

作　　者：刘克威[1] 谭安平[1] LIU Ke-wei;TAN An-ping(Engineering Training Center,The Engineering&Technical College of Chengdu University of Technology,Leshan 614000,China)

机构地区：[1]成都理工大学工程技术学院工程训练中心,四川乐山614000

出　　处：《塑性工程学报》2020年第8期159-165,共7页Journal of Plasticity Engineering

基　　金：成都理工大学工程技术学院基金资助项目(C122017031)。

摘　　要：在变形温度为300~450℃,应变速率为0.01~10 s^-1、压缩变形量为60%的条件下,利用Gleeble-1500热模拟机进行热压缩模拟实验,研究了7075铝合金的流变行为。通过微观组织观察,分析了平均晶粒尺寸随变形温度和应变速率的变化规律;根据应力-应变曲线,建立了周纪华流变应力本构方程,并进行优化和验证。结果表明,当变形温度为300℃时,平均晶粒尺寸随应变速率的增加而减小;当应变速率为0.1 s^-1时,平均晶粒尺寸随变形温度的增加先减小后增加;优化后的7075铝合金流变应力本构方程具有较高的精度,在应变ε≥0.1的情况下,拟合相关系数R为0.9862,平均相对误差AARE为5.54%。Hot compression tests for 7075 aluminum alloy were carried out by Gleeble-1500 thermal simulator under the condition of deformation temperatures of 300-450 ℃,strain rates of 0. 01-10 s^-1 and reduction of 60%,and the flow behavior of 7075 aluminum alloy was investigated. Through the microstructure observation,the change rule of average grain size with deformation temperature and strain rate was analyzed. According to the stress-strain curves,the ZHOU Jihua flow stress constitutive equation was established and the optimization and verification were carried out. The results show that the average grain size decreases with the increase of strain rate when deformation temperature is 300 ℃,and decreases first then increases with the increase of deformation temperature when strain rate is 0. 1 s^-1.The optimized flow stress constitutive equation for 7075 aluminum alloy has a higher precision,and the simnlation correlation coefficient R is 0. 9862 and the average relative error AARE is 5. 54% under the condition of strain ε≥0. 1.

关 键 词：7075铝合金 热变形 本构方程 微观组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]