Effect of minor Sc and Zr addition on microstructure and properties of ultra-high strength aluminum alloy  

添加微量Sc、Zr对超高强铝合金微观结构和性能的影响(英文)

作　　者：张伟[1] 邢远[1] 贾志宏[1] 杨晓芳[1] 刘庆[1] 朱昌洛[2] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]中国地质科学院矿产综合利用研究所,成都610041

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第12期3866-3871,共6页中国有色金属学报（英文版）

基　　金：Project(0211002605132)supported by Institute of Multipurpose Utilization of Mineral Resources,Chinese Academy of Geological Sciences,China;Project(0211005303101)supported by the Fundamental Research Funds for the Central Universities,China;Project(2010BB4074)supported by Natural Science Foundation Project of CQ CSTC,China;Project(2010ZD-02)supported by State Key Laboratory for Advanced Metals and Materials,China

摘　　要：The Al-9Zn-2.8Mg-2.5Cu-xZr-ySc alloys （x=0, 0.15%, 0.15%; y=0, 0.05%, 0.15%）, produced by low-frequent electromagnetic casting technology, were subjected to homogenization treatment, hot extrusion, solution and aging treatment. The effects of minor Sc and Zr addition on microstructure, recrystallization and properties of alloys were studied by optical microscopy （OM）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results show that Sc and Zr addition can refine grains of the as-cast alloy by precipitation of primary Al3（Sc,Zr） particles formed during solidification as heterogeneous nuclei. Secondary Al3（Sc,Zr） precipitates formed during homogenization treatment strongly pin the movement of dislocation and subgrain boundaries, which can effectively inhibit the alloys recrystallization. Compared with the alloy without Sc and Zr addition, the Al-Zn-Mg-Cu-Zr alloy with 0.05%Sc and 0.15%Zr shows the increase in tensile strength and yield strength by 172 MPa and 218 MPa, respectively. Strengthening comes from the contributions of precipitation, substructure and grain refining.采用低频电磁铸造技术制备Al-9Zn-2.8Mg-2.5Cu-x Zr-y Sc(x=0,0.15%,0.15%;y=0,0.05%,0.15%)合金,借助金相显微镜、扫描电镜、透射电镜、力学性能测试等手段分别对其均匀化、热挤压态、固溶态和时效态的组织与性能进行对比分析。结果表明:添加微量Sc和Zr,会在凝固过程中形成初生Al3(Sc,Zr),可显著细化合金铸态晶粒;均匀化时形成的次生Al3(Sc,Zr)粒子可以强烈钉扎位错和亚晶界,有效抑制变形组织的再结晶,显著提高合金的力学性能。与不含Sc、Zr的合金相比,含0.05%Sc和0.15%Zr的合金经固溶处理和峰值时效处理后其抗拉强度和屈服强度分别提高172 MPa和218 MPa,其强化作用主要来自含Sc、Zr化合物对合金起到的亚结构强化、析出强化和细晶强化。

关 键 词：aluminum alloy low-frequent electromagnetic casting inhibit recrystallization primary Al3（Sc Zr） particles secondary Al3（Sc Zr） particles substructure strengthening precipitation strengthening grain refining 

分 类 号：TG146.21[一般工业技术—材料科学与工程]