摘要
利用搅拌摩擦焊实现了2 mm厚7075-T6/6061-T6异种铝合金连接,并对材料放置位置和转速对接头成形与组织性能的影响进行了分析.结果表明,7075-T6铝合金置于前进侧时更有利于焊接过程中材料的迁移行为,焊缝成形及接头性能更优.当焊接速度为150 mm/min、转速为1000 r/min时,可获得内部无明显缺陷、外观良好的异种铝合金接头;相较于母材,热力影响区的小角度晶界含量增加,焊核区发生动态再结晶,小角度晶界转化为大角度晶界;接头拉伸性能随转速的增加,呈现先增加后减小的趋势.接头的平均抗拉强度和断后伸长率分别达到231 MPa和4.0%.接头的断裂位置位于6061侧焊核区,与接头硬度最小位置相吻合.
Friction stir welding technique was applied to 2mm thick 7075-T6/6061-T6 dissimilar aluminum alloys.The influence of rotating speed and material placement on the joint formation,microstructure and properties were studied.The results indicated that when the 7075-T6 aluminum alloy was placed on the advancing side,it is more conducive to material migration.The plates were joined successfully without welding defects and good surface formation when the welding speed is 150 mm/min and the rotating speed is 1000 r/min.Compared with the base metal,the thermo-mechanically affected zone had an increased content of low-angle boundaries.In the nugget zone,the low-angle boundaries converted to curve highangle boundaries because of dynamic recrystallization.With the increase of rotating speed,the tensile properties of the joint firstly increased and then decreased.The ultimate tensile strength of the joint reached 231 MPa,and the elongation reached 4.0%.the fracture locations of the joints all located in the nugget zone at the 6061-T6 side,which coincided with the position with the minimum hardness.
作者
高士康
周利
张欣盟
张军峰
李高辉
赵洪运
GAO Shikang;ZHOU Li;ZHANG Xinmeng;ZHANG Junfeng;LI Gaohui;ZHAO Hongyun(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin,150001,China;Shandong Provincial Key Laboratory of Special Welding Technology,Harbin Institute of Technology at Weihai,Weihai,264209,China;CRRC Changchun Railway Vehicles Co.,Ltd.,Changchun,130062,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2022年第6期35-42,I0004,I0005,共10页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51974100)
中车长春轨道客车股份有限公司委托课题(铝合金车体侧墙搅拌摩擦焊焊接接头优化设计)。
关键词
异种铝合金
搅拌摩擦焊
微观组织
力学性能
dissimilar aluminum alloys
friction stir welding
microstructure
mechanical property
