Pulsed TIG welding-brazing butt joints of aluminum-stainless steel thin plates with different fillers

Aluminum and stainless steel plates with 1.5 mm thickness are joined by pulsed TIG welding-brazing process with ER1100, ER4043 and ER2319 fillers, separately. Good weld formation can be obtained by adjusting appropriate pulse parameters. The effects of the fillers on microstructures and tensile strength of the joints are investigated. SEM results indicate that the thickness of the intermetallic compound (IMC) layer with ER2319 filler is about 2 μm, which is thinner than 2.5 μm of ER1100 filler and 3.5 μm of ER4043 filler. Moreover, the element distribution in both IMCs and welded seams with three fillers are different because of the different compositions of fillers. The results of mechanical property tests suggest that the joint strength with ER2319 filler is the highest, while the joint impact energy is the lowest. The joint with ER1100 filler exhibits the best comprehensive mechanical performance.