高应变速率轧制工艺对7050铝合金组织及力学性能的影响  

Effect of High Strain Rate Rolling Processing on Microstructures and Mechanical Properties of 7050 Aluminum Alloy

作　　者：严红革[1] 朱华明 廖杨 陈吉华[1] 夏伟军[1] 李贞贞 赵璐 YAN Hongge;ZHU Huaming;LIAO Yang;CHEN Jihua;XIA Weijun;LI Zhenzhen;ZHAO Lu(College of Materials Science and Engineering,Hunan University,Changsha 410082,China;TRIO METAL(GZ)Co.,Ltd.,Guangzhou 511340,China)

机构地区：[1]湖南大学材料科学与工程学院,湖南长沙410082 [2]广州众山精密科技有限公司,广东广州511340

出　　处：《湖南大学学报（自然科学版）》2022年第12期92-99,共8页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51871093)。

摘　　要：为了获得高体积分数小角度晶界和低体积分数再结晶组织以提高铝合金综合性能,探索了高应变速率轧制工艺对7050铝合金微观组织与力学性能间的影响,采用电子背散射分析、透射电镜等手段研究了不同工艺条件下的小角度晶界体积分数和动态析出相特征.研究结果表明,采用高应变速率轧制工艺能获得较高体积分数的小角度晶界,小角度晶界的比例随应变速率的增大而增大,但随轧制温度的升高而降低.当轧制参数为370℃/20 s^(-1)时,小角度晶界比例高达95.6%.轧制参数为400℃/20 s^(-1)的板材经470℃/0.5 h短时固溶及120℃/24 h时效处理后,有较好的综合力学性能,其中抗拉强度为530 MPa,屈服强度为442 MPa,断裂伸长率为19.1%.在相同轧制温度下,应变速率为20 s^(-1)时的力学性能优于应变速率为10 s^(-1)的样品.To obtain high volume fraction low angle grain boundary(LAGBs)and low volume fraction recrystallization microstructure so as to improve the comprehensive properties of aluminum alloy,the effects of High Strain Rate Rolling(HSRR)processing parameters on microstructures and mechanical properties of 7050 aluminum alloy were explored.Electron backscatter diffraction(EBSD),Transmission Electron Microscopy(TEM)were used to characterize the volume fraction of low angle-grain boundarys(LAGBs)and dynamic precipitates.The results show that a high fraction of LAGBs can be obtained by HSRR,and the fraction of LAGBs increases with the increasing strain rate but decreases with the temperature.The fraction of LAGBs is 95.6%with the rolling parameter of 370℃/20 s^(-1).The alloy rolled at 400℃/20 s^(-1) exhibits good comprehensive mechanical properties after 470℃/0.5 h short-term solution treatment and 120℃/24 h aging treatment,with the ultimate tensile strength of 530 MPa,the yield strength of 442 MPa,the elongation at fracture of 19.1%.The mechanical properties of the plates rolled with the strain rate of 20 s^(-1) are better than that with the strain rate of 10 s^(-1) at the same rolling temperature.

关 键 词：7050铝合金 高应变速率轧制 小角度晶界 时效 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]