采用填充式摩擦点焊对2mm厚的5A06铝合金与AZ31B镁合金进行工艺试验.利用金相显微镜、扫描电镜和拉伸试验机分析填充式摩擦点焊的接头组织和力学性能.结果表明,采用填充式摩擦点焊可获得成形美观、力学性能良好的接头,其焊点抗剪切力可达1 865 N,焊点在循环应力作用下的疲劳寿命达到66 000次,断裂方式为脆性断裂.微观组织分析表明,界面处镁、铝元素更易在偏铝母材一侧形成Mg17Al12,Al3Mg2等金属间化合物,而界面层厚度是保证力学性能的关键.
Experiments of friction spot welding was developed to joining magnesium alloy and aluminum alloy ,and acceptable joints without obvious defects were obtained.The microstructure and mechanical properties of joint interface were analysed in details by scanning electron microscopy and testing machine.The results showed that the Shear force which the joints are able to bare was over 1 865 N, and these joints was possessed of over 66 000 times fatigue life under the action of cyclic stress, and the fracture mode was mostly brittle fracture.The microstructure showed that the intermetallic compounds like MgITAl12 and A13Mg2 were more easily formed in partial aluminum side of base metal by Mg and A1 elements of interface,and the thickness of interface layer is the key part to ensure the mechanical properties of the joint.