Microstructure and Joint Strength of Similar- and Dissimilar Lap Joints Fabricated by Several Advanced Solid-State Welding Methods

Both similar- and dissimilar metal joints, which are difficult to be welded by using ordinary fusion welding methods, were successfully obtained by using several advanced high-speed solid-state joining methods. (1) Al/Al, Cu/Cu, Al/Fe(Steel), Al/Cu, Al/Ni, Cu/Ni and Al/Bulk metallic glass lap joints were magnetic pulse welded by means of mutual high-speed oblique collision of metal sheets at a high speed of about 500m/s. (2) 2xxx aluminum alloy pins were stud-welded to 5xxx alloy aluminum sheets and several kinds of plated steel sheets at a high speed by using a specially designed discharge circuit. The welding was achieved within a few milliseconds without producing any weld marks on the back surface of the plate. (3) 6022 aluminum alloy sheets were friction stir spot welded to steel sheets and various kinds of galvanized and aluminum-plated steel sheets. The welding was achieved within a few seconds. For those joints, joint strength and characteristic joint interface morphology were investigated.