2195-T6铝锂合金搅拌摩擦焊接头微观组织结构与力学性能  

Microstructure and mechanical properties of 2195-T6 Al-Li alloy joint prepared by friction stir welding

作　　者：戴翔 石磊[1] 武传松[1] 蒋元宁 高嵩 傅莉[3] DAI Xiang;SHI Lei;WU Chuansong;JIANG Yuanning;GAO Song;FU Li(Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(MOE),Shandong University,Jinan,250061,China;School of Mechanical&Automotive Engineering,Qilu University of Technology,Jinan,250353,China;State Key Laboratory of Solidification,Northwestern Polytechnical University,Xi'an,710072,China)

机构地区：[1]山东大学,材料液固结构演变与加工教育部重点实验室,济南250061 [2]齐鲁工业大学,济南250353 [3]西北工业大学,凝固技术国家重点实验室,西安710072

出　　处：《焊接学报》2022年第6期25-34,I0004,共11页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51905309,52035005);凝固技术国家重点实验室开放课题(SKLSP201912)。

摘　　要：采用搅拌摩擦焊对2 mm厚的2 195-T6铝锂合金进行焊接,利用OM,SEM,EBSD等分析技术探讨焊接速度对接头组织结构与力学性能的影响.结果表明,搅拌头转速为800 r/min、焊接速度在120~210 mm/min范围内,焊核区晶粒均较为细小,平均晶粒尺寸约为1μm.随着焊接速度的提高,大角度晶界含量增大,焊核区的{110}<110>织构和{011}<100>戈斯织构消失.接头硬度的最低值均出现在后退侧热影响区,且在焊接速度为180 mm/min时,接头的抗拉强度与断后伸长率达到最大值,最大抗拉强度为467 MPa,约为母材的86.3%,此时断后伸长率为5.0%,断裂模式为韧性断裂,但断口呈现一定的脆性断裂特征.Friction stir welding was carried out on 2 mm thick 2195-T6 Al-Li alloy sheets. Effect of welding speed on microstructures and mechanical properties of the joint was investigated by OM, SEM, EBSD and other analytical techniques. The results show that at the rotational speed of 800r/min and the welding speeds of 120-210 mm/min, the grains in the nugget zone are all relatively smaller, with the average grain size is above 1 μm. With an increase of welding speed,the ratio of high angle grain boundaries is increased.{110}<110> and {011}<100> Goss texture are disappear. The lowest hardness are found at the heat affected zone of the retreating side. Both tensile strength and elongation reach their maximum value at the welding speed of 180 mm/min, with a maximum tensile strength of 467 MPa, which is about 86.3%of the base metal, while the maximum elongation is about5.0%. The fracture mode is ductile fracture, while the fracture also shows partial brittle fracture characteristic.

关 键 词：铝锂合金 搅拌摩擦焊 焊接速度 微观组织 力学性能 

分 类 号：TG442[金属学及工艺—焊接]