Microstructural evolution and its influence on mechanical and corrosion behaviors in a high-Al/Zn containing duplex Mg-Li alloy after friction stir processing  

作　　者：Yixing Zhu Mengran Zhou Yingxin Geng Shun Zhang Tongzheng Xin Gaoqiang Chen Yifan Zhou Xiaoyu Zhou Ruizhi Wu Qingyu Shi 

机构地区：[1]State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment,Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China [2]Key Laboratory for Advanced Materials Processing Technology,Ministry of Education,Beijing 100084,China [3]Key Laboratory of Superlight Materials&Surface Technology(Ministry of Education),Harbin Engineering University,Harbin 150001,China [4]Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province),School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China [5]Beijing North Vehicle Group Corporation,Beijing 100072,China

出　　处：《Journal of Materials Science & Technology》2024年第17期245-255,共11页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(grant Nos.U23A20541 and 52305385).

摘　　要：Ultralight Mg-Li alloys offer promising applications across various fields.Mg-Li alloys enriched with Al and Zn hold theoretical potential for achieving excellent mechanical strength and corrosion resistance.However,the structural and performance characteristics of such Mg-Li alloys,particularly after thermo-mechanical processing,remain inadequately explored and understood.This study investigated the mi-crostructural evolution of a Mg-9Li-5Al-4Zn alloy after friction stir processing and its consequent effects on the mechanical and corrosion performance.The grain size of the alloy was effectively refined and sta-bilized during friction stir processing at various heat inputs.The yield strength of the alloy increased by 86.4%after friction stir processing under the highest heat input condition,which was attributed to fine grain strengthening,solid solution strengthening and dispersion strengthening.Concurrently,the alloy ex-perienced a slight decrease in elongation after the friction stir processing.The alloy subjected to friction stir processing with the highest heat input exhibited a minimal corrosion current density of 6.10×10^(−6) A/cm^(2),which was only 25%of the base metal.The enhanced anti-corrosion properties can be attributed to the dispersion and distribution of precipitated particles induced by friction stir processing,which hin-dered the micro-galvanic corrosion and promoted the generation of a compact surface film,leading to minimal and uniform corrosion.This investigation can be significant for understanding the metallurgical mechanisms and performance evolution of Mg-Li alloys during thermomechanical processes.

关 键 词：Mg-Li-Al-Zn alloy Friction stir processing Microstructure evolution Thermal-mechanical stability Corrosion behavior 

分 类 号：TG146.22[一般工业技术—材料科学与工程]