挤压-固溶态7A43铝合金的室温压缩微观组织及变形行为  

Microstructure and deformation behavior of extruded 7A43 alloy in solid solution state under room temperature compression

作　　者：邵虹榜 黄元春 王端志[2,3] 郭晓芳 SHAO Hongbang;HUANG Yuanchun;WANG Duanzhi;GUO Xiaofang(Light Alloy Research Institute,Central South University,Changsha 410083,China;College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China;Shandong Long March Rocket Co.,Ltd.,Yantai 265100,Shandong,China)

机构地区：[1]中南大学轻合金研究院,长沙410083 [2]中南大学机电工程学院,长沙410083 [3]山东长征火箭有限公司,山东烟台265100

出　　处：《材料工程》2023年第5期76-86,共11页Journal of Materials Engineering

基　　金：国家自然科学基金项目(U1837207);中南大学中央高校基本科研业务费专项资金项目(2021zzts0152)。

摘　　要：采用Gleeble-3500试验机对挤压-固溶态7A43铝合金(Al-6.0Zn-2.1Mg-0.15Cu-0.15Zr,质量分数/%)进行应变速率为0.001~1 s^(-1)、变形量为50%的室温压缩变形,并借助扫描电子显微镜(SEM)、背散射电子显微分析(EBSD)以及X射线分析(XRD)等手段对变形微观组织进行表征。结果表明,随着变形速率的提高,整体晶粒尺寸因畸变程度增加而减小的同时,合金内部晶格应变和位错密度逐渐增大。高应变速率条件下微观组织中的亚结构组分增加,粗大纤维组织被细小的等轴晶粒取代。测得的应力-应变曲线表明,累积应变量和应变速率对流变应力水平具有较大影响,基于得到的实验数据构建了Fields-Backofen(F-B)本构方程,预测值和实验值之间的相关系数(R)和平均绝对相对误差(AARE)分别为0.991069和3.667%,表明所建立的模型较准确地描述了7A43铝合金室温变形流变行为。The compression deformation test on extruded-solid solution 7A43 alloy(Al-6.0Zn-2.1Mg-0.15Cu-0.15Zr,mass fraction/%)was conducted by Gleeble-3500 machine with strain rate of 0.001 s^(-1) to 1 s^(-1) at room temperature,and the microstructural features were characterized by scanning electron microscopy(SEM),backscattered electron microscopy(EBSD)and X-ray differaction analysis(XRD).It is revealed that with the increase of strain rate,the average grain size decreases due to severe microstructural distortion,whilst the lattice strain and dislocation density in the alloy gradually increase.Dynamic recovery substructure components in the microstructure are enhanced,and the coarse deformed grains are replaced by fine equiaxed grains under high deformation rate conditions.A Fields-Backofen(F-B)constitutive model was constructed based on the experimental stress-strain data,the correlation coefficient(R)and average absolute relative error(AARE)between the experimental and predicted values are 0.991069 and 3.667%,respectively,which provide a good description of the model for deformation rheological behavior of 7A43 aluminum alloy at room temperature.

关 键 词：7A43铝合金 室温变形 微观组织 流变行为 本构模型 

分 类 号：TG146.21[一般工业技术—材料科学与工程]