2012 Volume 43 Issue 6 Pages 1413-1418
Recently, there are strong demands for lightweight, fuel-efficient cars. An effective joining technique to join light metals, such as aluminum and magnesium alloys, with steel is required. However, magnesium alloy and steel are especially difficult pair of metals to join. Due to not only magnesium alloy's surface oxide, but also their phase separating nature, magnesium and steel do not form an intermetallic at the joint interface. We aimed to join such magnesium alloy and steel by using Zn-Mg eutectic reaction and Al content in magnesium alloy; Zn layer was inserted between magnesium alloy and steel as plating on steel. The experiment was performed using a conventional resistance spot welding machine, and joint strength was evaluated by tensile strength tests. It was found that magnesium alloy surface oxide are removed along with eutectic melt at low temperature, and at the same time, thin and uniform intermetallic layers of Fe-Al and Al-Mg were formed at the joint interface.
