Al-9.0Zn-2.5Mg-2.2Cu-0.2Zr-xSc铝合金组织和力学性能研究  

Study on the Microstructure and Mechanical Properties of Al-9.0Zn-2.5Mg-2.2Cu-0.2Zr-xSc Aluminum Alloy

作　　者：常昭楠 刘奎仁 刘一 韩庆 陈建设 李斌川 CHANG Zhao-nan;LIU Kui-ren;LIU Yi;HAN Qing;CHEN Jian-she;LI Bin-chuan(School of Metallurgy,Northeastern University,Shenyang 110819,China;Shenyang Key Laboratory of Nonferrous Metal Resource Recycling and Utilization,Shenyang 110819,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110819 [2]沈阳市有色金属资源循环利用重点实验室,辽宁沈阳110819

出　　处：《稀有金属与硬质合金》2025年第2期54-61,共8页Rare Metals and Cemented Carbides

摘　　要：设计了一种Al-9.0Zn-2.5Mg-2.2Cu-0.2Zr-xSc高强铝合金,并对铸态合金进行均匀化退火、热轧、固溶时效处理,分析了采用双级均匀化退火的原因及双级均匀化退火对铸态合金微观组织的影响,研究了固溶温度对合金微观组织及力学性能的影响,以及Sc含量对合金力学性能的影响。结果表明:采用双级均匀化退火不仅能消除合金的铸造应力,使Zn、Mg、Cu元素分布更均匀,还能减小晶界无沉淀带(PFZ)的宽度,有利于提升合金性能。随固溶温度升高,合金板材再结晶程度增大,合金中残留第二相数量变少。相较于其他固溶温度(450、460、480℃),经470℃×2 h固溶处理并进行120℃×24 h时效处理后合金的抗拉强度最大。随着Sc含量由0增至0.6%,合金抗拉的强度先升高后降低,断后伸长率呈下降趋势。当Sc含量为0.42%时,合金的抗拉强度最大。High-strength aluminum alloy Al-9.0Zn-2.5Mg-2.2Cu-0.2Zr-xSc was designed,and its as-cast alloy was subjected to homogenizing annealing,hot rolling,solid solution and aging treatments.The reasons for adopting the two-stage homogenizing annealing and its effects on the microstructure of the as-cast alloy were analyzed,and the influence of the solid solution temperature on the microstructure and mechanical properties of the alloy,as well as the Sc content on the mechanical properties of the alloy,were also stu-died.The results show that the use of two-stage homogenizing annealing can not only eliminate the casting stress of the alloy and make the distribution of Zn,Mg and Cu elements more uniform,but also reduce the width of the grain boundary precipitate-free zone(PFZ),which is conducive to the improvement of alloy properties.As the solid solution temperature increases,the degree of recrystallization of the alloy sheet increases,and the number of residual second phases in the alloy decreases.Compared with other solid solution temperatures(450℃,460℃,480℃),the tensile strength of the alloy after solid solution treatment at 470℃for 2 h and aging treatment at 120℃for 24 h is the highest.With the increase of Sc content from 0 to 0.6%,the tensile strength of the alloy first increases and then decreases,and the elongation at break shows a decreasing trend.When the Sc content is 0.42%,the tensile strength of the alloy is the highest.

关 键 词：高强铝合金 SC 均匀化退火 固溶温度 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]