Microstructural evolution of Al-Cu-Li alloys with different Li contents by coupling of near-rapid solidification and two-stage homogenization treatment

作     者：Lei Luo Liang-shun Luo Zhi-ping Li Hong-ying Xia Yan-qing Su Liang Wang Jing-jie Guo Heng-zhi Fu Lei Luo;Liang-shun Luo;Zhi-ping Li;Hong-ying Xia;Yan-qing Su;Liang Wang;Jing-jie Guo;Heng-zhi Fu

作者机构：School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China 

出 版 物：《China Foundry》 (中国铸造（英文版）)

年 卷 期：2020年第17卷第3期

页      面：190-197页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：the National Key Research and Development Program of China(Grant No.2017YFA0403804) the National Natural Science Foundation of China(Grant No.51425402) 

主　　题：Al-Cu-Li alloys ultra-low density near-rapid solidification two-stage homogenization treatment microstructural evolution 

摘      要：Microstructural improvement of Al-Cu-Li alloys with high Li content plays a critical role for the acquisition of excellent mechanical properties and ultra-low *** this regard,the Al-Cu-Li alloy castings with high Li content from 1.5 wt.%to 4.5 wt.%were prepared by near-rapid solidification,followed by two-stage homogenization treatment(490℃/16 h and 530℃/16 h).The microstructural evolution and solidification behavior of the as-cast and homogenized alloys with different Li contents were systematically studied by combining experiments with calculations by Pandat *** results indicate that with the increase of Li content,the grain sizes decrease,the solution ability of Cu in the matrixα-Al phase increases,while the content of secondary dendrites increases and the precipitated phases change from low melting point phases to high melting point phases under the near-rapid ***,by the coupling of near-rapid solidification and two-stage homogenization,the metastable precipitated phases(Al7Cu4Li and AlCu3)can be dissolved effectively in the alloys with Li content of 1.5 wt.%-2.5 wt.%;moreover,the stable precipitated phases(Al6CuLi3 and Al2CuLi)uniformly distribute at the grain boundaries in the alloys with Li content of 3.5 wt.%-4.5 wt.%.As a result,the refined and homogenized microstructure can be obtained.