Study on microstructure and properties of resistance spot welding of Mg/Ti dissimilar materials
Fei Liu, Qinglei Hou, Hao Hu, Yong Ma, Shaowei Ning, Yucheng Wu
Abstract
The dissimilar material of AZ31 Mg alloy and TA15 Ti alloy were welded by resistance spot welding. The influence of welding current on the interface of nuggets is studied. The microstructure, hardness, tensile strength and fracture surface of joints are analysed. The results indicate that when the electrode pressure and welding time are determined, the failure load of the joint can be improved by the increase in the welding current; however, excessively high welding current will cause cracks near the interface. Under the welding current of 14.5 kA, the electrode pressure of 0.22 MPa and the welding time of 200 ms, the maximum failure load of the joint can reach 4.79 kN, which is almost the same as the shear strength of AZ31B magnesium alloy base metal.