Microstructural evolution of Al-8.59Zn-2.00Mg-2.44Cu during homogenization

作     者：Wen-xiang Shu Jun-cheng Liu Long-gang Hou Hua Cui Jun-tao Liu Ji-shan Zhang 

作者机构：State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing School of Materials Science and Engineering University of Science and Technology Beijing State Key Laboratory for Fabrication and Processes of Nonferrous Metals General Research Institute for Nonferrous Metals 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2014年第21卷第12期

页      面：1215-1221页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 0806[工学-冶金工程] 08[工学] 0708[理学-地球物理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the Fundamental Research Funds for the Central Universities of China (No. FRF-TD-12-001) the Beijing Laboratory of Modern Traffic Metal Materials and Processing Technology 

主　　题：aluminum alloys homogenization microstructural evolution phase composition thermodynamic calculations 

摘      要：The microstructural evolution and phase transformations of a high-alloyed Al-Zn-Mg-Cu alloy （Al-8.59Zn-2.00Mg-2.44Cu,wt%） during homogenization were investigated. The results show that the as-cast microstructure mainly contains dendritic α（Al）, non-equilibrium eutectics （α（Al） ＋ Mg（Zn,Al,Cu）2）, and the θ （Al2Cu） phase. Neither the T （Al2Mg3Zn3） phase nor the S （Al2CuMg） phase was found in the as-cast alloy. The calculated phase components according to the Scheil model are in agreement with experimental results. During homogenization at 460℃, all of the θ phase and most of the Mg（Zn,Al,Cu）2 phase were dissolved, whereas a portion of the Mg（Zn,Al,Cu）2 phase was transformed into the S phase. The type and amount of residual phases remaining after homogenization at 460℃ for 168 h and by a two-step homogenization process conducted at 460℃ for 24 h and 475℃ for 24 h （460℃/24 h ＋ 475℃/24 h） are in good accord with the calculated phase diagrams. It is concluded that the Al-8.59Zn-2.00Mg-2.44Cu alloy can be homogenized adequately under the 460℃/24 h ＋ 475℃/24 h treatment.