Microstructural evolution of new type Al-Zn-Mg-Cu alloy with Er and Zr additions during homogenization  

新型Er、Zr微合金化Al-Zn-Mg-Cu合金在均匀化中的显微组织演变（英文）

作　　者：Hao WU Sheng-ping WEN Jun-tai LU Zhen-peng MI Xian-long ZENG Hui HUANG Zuo-ren NIE 吴浩;文胜平;卢军太;米振鹏;曾宪龙;黄晖;聂祚仁(北京工业大学材料科学与工程学院,北京100124)

机构地区：[1]School of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第7期1476-1482,共7页中国有色金属学报（英文版）

基　　金：Project(2012CB619503) supported by the National Basic Research Program of China;Project(51201003) supported by the National Natural Science Foundation of China;Project(2142007) supported by Natural Science Foundation of Beijing,China

摘　　要：A comprehensive study on the microstructural evolution of a new type Al-Zn-Mg-Cu-Er-Zr alloy duringhomogenization was conducted by optical microscope,scanning electron microscope,transmission electron microscopy and X-raydiffraction analysis.The results show that serious segregation exists in as-cast alloy,and the primary phases are T(AlZnMgCu),S(Al2CuMg)and Al8Cu4Er,which preferentially locate in the grain boundary regions.The soluble T(AlZnMgCu)and S(Al2CuMg)phases dissolve into the matrix gradually during single-stage homogenized at465°C with prolonging holding time,but the residualAl8Cu4Er phase cannot dissolve completely.Compared with the single-stage homogenization,both a finer particle size and a highervolume fraction of L12-structured Al3(Er,Zr)dispersoids can be obtained in the two-stage homogenization process.A suitablehomogenization scheme for the present alloy is(400°C,10h)+(465°C,24h),which is consistent with the results of homogenizationkinetic analysis.通过使用光学显微镜、扫描电镜、透射电镜及X射线衍射等手段研究一种新型Er、Zr微合金化Al-Zn-Mg-Cu合金在均匀化过程中的显微组织演变。结果表明:铸态合金组织存在严重的偏析,此时合金中含有大量的T(AlZnMgCu)、S(Al_2CuMg)和Al_8Cu_4Er相,这些初生相大量偏聚于晶界。随着在465°C单级均匀化处理的进行,第二相含量大幅度降低,可熔的T相和S相会逐步地熔入基体,但Al8Cu4Er相不能完全消除,仍有少量残留。相对于单级均匀化工艺,合金在双级均匀化处理时不仅能够消除铸态合金偏析组织,而且能够析出大量细小弥散分布的L1_2结构的Al_3(Er,Zr)相。结合均匀化动力学分析,可以得出合金合理的均匀化热处理制度为(400°C,10 h)+(465°C,24 h)。

关 键 词：Al-Zn-Mg-Cu-Er-Zr alloy HOMOGENIZATION microstructural evolution primary phases Al3(Er Zr) particles 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG292[金属学及工艺—金属材料]