Influence of Annealing Treatments on Microstructure and Mechanical Properties of an Extruded Mg AZ31/Al 7050 Laminate

作     者：Yang Wu Yun-Chang Xin Xiang-Sheng Xia Bo Feng Yan-Bin Wang Zu-De Zhao 

作者机构：Southwest Technology and Engineering Research Institute International Joint Laboratory for Light Alloys College of Materials Science and Engineering Chongqing University Guangdong Institute of Materials and Processing Guangdong Academy of Sciences 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2019年第32卷第2期

页      面：227-234页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：supported by the Fundamental Research Funds for the Central Universities(106112016CDJXZ138804) the ‘‘111’’ Project(B16007)by the Ministry of Education and the State Administration of Foreign Experts Affairs of China 

主　　题：Laminate composite Annealing Microstructure Texture Mechanical property 

摘      要：Mg AZ31/A1 7050 laminate was fabricated by co-extrusion directly from the as-cast Mg AZ31 and Al 7050 billets. The influence of annealing temperature and annealing time on microstructure and mechanical behavior of the extruded Mg/Al laminate was systematically studied. Results show that annealing treatments at 250 ℃ for 3 h or at 350 ℃ for 3 h do not result in an obvious grain coarsening of Mg layer and cannot remove the heterogeneous structure. Annealing does not vary texture in the Mg layer, a large fraction of //ND and a small fraction of //TD, but the intensity of component //ND weakens to some extent. Lamellar microstructure in the A1 layer remains after annealing at250 ℃ for 3 h or at 350 ℃ for 3 h. High fractions of the texture components S and cube exist in the extruded sample, and annealing treatment hardly changes their fractions. Post-annealing treatment will largely reduce yield strength of extruded plate and increase plasticity slightly. The yield strength drops from 302 MPa to 206 MPa after annealing at 250 ℃ for 3 h and to 141 MPa after annealing at 350 ℃ for 3 h. The elongation to fracture increases from 1.5% to 5.4% after annealing at 250 ℃ for 3 h and to 4.8% at 350 ℃ for 3 h. The corresponding mechanism was discussed.