Q235碳素结构钢与6061铝合金搅拌摩擦点焊的试验研究  

Experimental Study on Friction Stir Spot Welding of Q235 Carbon Structural Steel and 6061 Aluminum Alloy

作　　者：陆宝山[1] 李有智[1] 关集俱 LU Baoshan;LI Youzhi;GUAN Jiju(Department of Precision Manufacturing Engineering,Suzhou Institute of Industrial Technology,Suzhou 215104,China)

机构地区：[1]苏州工业职业技术学院精密制造工程系,江苏苏州215104

出　　处：《热加工工艺》2022年第3期140-145,共6页Hot Working Technology

基　　金：江苏省自然科学基金青年基金项目(BK20170373);国家自然科学基金青年基金项目(51805345);苏州市重点实验室资助项目(SZS201815);江苏高校“青蓝工程”资助项目(2019)

摘　　要：为验证Q235碳素结构钢与6061铝合金搅拌摩擦点焊的可行性,将厚度2 mm的Q235钢板(上板)分别与厚度5 mm和10 mm的6061铝合金板(下板),在主轴转速1200 r/min、轴向负荷12 kN以及不同的焊接挤压时间下进行搅拌摩擦点焊试验。结果表明,对于5 mm厚的铝合金板,钢/铝界面温度在8 s时迅速上升至6061铝合金的液相线温度(652℃),并在15 s时达到740℃,焊接后焊缝处的破坏负荷达到10〜15 kN;对于10 mm厚的铝合金板,界面温度大约在20 s时上升到652℃,在45 s时达到740℃,焊缝处的破坏负荷达到18〜22 kN。在Q235钢/6061铝合金接合面的铝合金板中央区域发生熔化,形成铁与铝的熔覆金属层,经XRD检测确定为Fe_(2)Al_(5)和Fe_(4)Al_(13)。使用SEM观察比较,发现5mm厚的铝合金板在接合面处的熔覆金属层厚度比10mm厚的铝合金板的要厚,较厚的熔覆金属层更易形成裂缝,从而削弱了其破坏负荷。In order to verify the feasibility of friction stir spot welding of Q235 carbon structural steel and 6061 aluminum alloy,the Q235 steel sheet with thickness of 2 mm as upper sheet and the 6061 aluminum alloy plate with thickness of 5 mm and 10 mm as lower plate were welded respectively under the test conditions of spindle speed 1200 r/min,axial load of 12 kN and different extrusion time.The results show that for the 5 mm thick aluminum alloy plate,the temperature of the steel/Al interface rises rapidly to the liquid-phase line temperature(652℃)of the 6061 aluminum alloy at 8 s,and it reaches 740℃ at 15 s,and the failure load of the weld seam is 10-15 kN after welding;for the 1Omm-thick aluminum alloy plate,the interface temperature rises to 652℃ at about 20 s,and to 740℃ at 45 s,the failure load of the weld seam reaches 18-22 kN.The central area of aluminum alloy plate in the interface of Q235 steel/6061 aluminum alloy melts to form a cladding metal layer containing iron and aluminum,which is Fe_(2)Al_(5) and Fe_(4)Al_(13) determined by XRD.It is found that the thickness of cladding metal layer of the 5 mm-thick aluminum alloy plate at the joint surface is thicker than that of the aluminum alloy plate with 10 mm thickness analyzed by using SEM,and the thicker cladding metal layer is easier to form crack,thus weakens the failure load.

关 键 词：Q235碳素结构钢 6061铝合金 摩擦搅拌点焊 破坏负荷 

分 类 号：TG45[金属学及工艺—焊接]