Dissimilar Metal Lap Welding of A5052 Aluminum Alloy and TP340 Pure Titanium Plates by using Magnetic Pulse Welding

Abstract

　Dissimilar metal lap welding of A5052 aluminum alloy and TP340 pure titanium plates was performed by using magnetic pulse welding, and interfacial microstructure and joint strength were investigated. The A5052 aluminum alloy plate and the TP340 pure titanium plate were used for a flyer plate and a parent plate, respectively, and charging energy stored in a capacitor and plate gap between the aluminum plate and the titanium plate were changed to fabricate the joint. The welding was achieved at the charging energy above 2.5 kJ and at the plate gap above 1.0 mm. The range of the weldable charging energy increased with decreasing the plate gap. The width of the welded area increased with increasing the charging energy or increasing the plate gap. The welding interface exhibited characteristic wavy morphology. Intermediate layer was produce along the wavy interface and it was composed of fine Al-Ti supersaturated solid solution grains with approximately 100 nm diameter. In all joints, fracture by the tensile-shear test occurred at the aluminum base metal. The formation of the refined supersaturated solid solution grain is considered to result in interfacial strength enhancement of the aluminum/titanium joint.