汽车车身用铝合金冷金属过渡点塞焊工艺分析

Analysis on cold metal transfer spot plug welding process of aluminum alloys for automobile body

采用Al Si5铝合金焊丝,冷金属过渡方法对汽车车身用6061铝合金进行了搭接点塞焊试验,研究了送丝速度、铝板孔直径、点塞焊时间对点塞焊接头焊点直径、焊核直径和拉伸载荷的影响.结果表明,送丝速度主要影响焊点直径的大小,点塞焊时间和铝板孔直径主要影响焊核直径和拉伸载荷.接头拉伸载荷主要取决于焊核直径的大小,焊核直径越大,拉伸载荷越大,与焊点直径关系不大.接头为典型的熔焊接头,焊缝主要由α-Al固溶体和Al-Si共晶相组成,点塞焊接头断裂方式为撕裂型断裂.

Cold metal transfer lap spot plug welding experiments of 6061 aluminum alloy used in the automobile body were carried out by using AlS i5 filler metal. The effects of wire feeding rate,spot plug welding time and hole diameter in aluminum plate on welding spot diameter,nugget diameter and tensile load were investigated. The experimental results indicate that wire feeding rate mainly affects welding spot diameter. Spot plug welding time and hole diameter in aluminum plate have a significant effect on nugget diameter and tensile load. Tensile load of the joint primarily depends on the nugget diameter and increases with the increase of nugget diameter,but welding spot diameter has little effect on the tensile load. The joint belongs to the typical fusion welded joint. The weld metals are composed of α-Al solid solution and Al-Si eutectic phase. Tear results in fracture in tensile test of Al-Al spot plug welded joint.