对轨道车体用7xxx铝合金接头进行MIG对接焊，填充金属选用直径为1.2mm的ER 5087铝合金焊丝，焊后对焊接接头进行拉伸，微观金相组织观测......

The microstructure of the as-cast, as-solution-treated and as-aged wrought magnesium alloy ZK60 was studied. The results......