Microstructure and properties of aluminum 6061/copper H60 welded joint by tig conduction welding

To achieve the reliable joining of aluminum 6061 and copper H60, copper alloy was heated by TIG arc to melt the aluminum alloy. The microstructure of the joint was analyzed by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The effect of welding current on the microstructure and properties of the joints was investigated. The results revealed that the microstructures of the joint are copper substrate/ Al4Cu9layer/Al2Cu layer/α-Al+Cu5Zn8+Al2Cu phases/aluminum substrate. The thickness of Al4Cu9+Al2Cu layers near to the copper substrate is increased with the increase of welding current. However, when the welding current reached 110 A, micro-cracks were observed along the copper substrate. The tensile load increases with the increase of welding current until maximum tensile load of 1.67 kN was reached, and then decreases at higher welding current.