6082铝合金回填式搅拌摩擦点焊对接接头的组织和性能研究  

Microstructure and Mechanical Properties of 6082 Aluminum Alloy Refill Friction Stir Spot Welding Butt Joint

作　　者：刘颖辉 杨德云 LIU Yinghui;YANG Deyun(College of Marine Engineering,Beihai Campus,Guilin University of Electronic Science and Technology,Beihai 536000,China;College of Intelligent Equipment Engineering,Wuxi Taihu University,Wuxi 214064,China)

机构地区：[1]桂林电子科技大学(北海校区)海洋工程学院,广西北海536000 [2]无锡太湖学院智能装备工程学院,江苏无锡214064

出　　处：《热加工工艺》2024年第3期19-23,28,共6页Hot Working Technology

摘　　要：将回填式搅拌摩擦点焊首次应用到铝合金的对接过程中。本文研究了搅拌头转速对2 mm厚的6082铝合金对接接头显微组织和性能的影响。结果表明,使用1.6 mm的搅拌头下压量可有效避免接头底部未焊合。但当转速为1950 r/min时,搅拌套筒回抽路径的外沿形成热裂纹。焊核区晶粒明显细化,当转速为1350 r/min时,焊核区平均晶粒尺寸由母材的30.84μm减小至8.43μm;热机影响区和焊核区的织构也发生明显变化。焊缝的硬度整体上高于母材的,这与焊缝中较小的晶粒有关。当转速为1650 r/min时接头的强度最高,达到190 MPa;当转速为1950 r/min时,因热机影响区/焊核区截面的裂纹缺陷影响,接头的抗拉强度仅为121 MPa。Refill friction stir spot welding(RFSSW)is innovatively applied to butt welding of aluminum alloy.The effect of the tool rotating speed on the microstructure and properties of the 2 mm thick 6082 aluminum alloy butt welded joint was studied.The results show that incomplete bonding at the bottom part of the joint can be effectively avoided by using the tool plunge depth of 1.6 mm.When the rotating speed is 1950 r/min,hot crack appears on the outer edge of the stir sleeve retracting path.The grains of the stir zone is obviously refined,and when the rotating speed is 1350 r/min,the average grain size of the stir zone decreases from 30.84μm of the base material to 8.43μm.The textures of the thermal mechanical affected zone(TMAZ)and stir zone(SZ)change obviously.The hardness of the joint is generally higher than that of the base material,which is related to the smaller grains.When the rotating speed is 1650 r/min,the tensile strength of the joint is the maximum of 190 MPa.When the rotating speed is 1950 r/min,the tensile strength of the joint is only 121 MPa due to the cracks at the interface between the SZ and the TMAZ.

关 键 词：回填式搅拌摩擦点焊 对接焊 6082铝合金 晶粒 织构 

分 类 号：TG453.9[金属学及工艺—焊接]