Surface Structure and Strength Analysis of Friction Stir Welding in Thin Sheet Dissimilar Magnesium Alloys

In response to the growing trend of miniaturization in electronic products, there is an increasing focus on temperature control and material selection in the manufacturing process. Dissimilar joining of magnesium alloys, commonly used in electronics, has gained significant attention. This study investigates friction stir welding of thin dissimilar magnesium alloy sheets using a micro five-axis milling machine. AZ31 and LZ91 alloys were joined, and the welding parameters, including rotational speed and traverse speed, were carefully designed and monitored. Surface imaging, microstructure, tensile strength, and microhardness were analyzed to assess the results. The findings revealed that due to the rapid heat dissipation of the materials, temperature increases were minimal. At a rotational speed of 15,000 rpm and a traverse speed of 10 mm/min, optimal surface structure, hardness 77 HV, and tensile strength 151 MPa were achieved. The study successfully demonstrated the potential of using friction stir welding for joining thin dissimilar magnesium alloy sheets in industrial applications.