Experimental study on dissimilar TIG welding-brazing of 5A06 aluminum alloy to SUS321 stainless steel

Dissimilar metals TIG welding-brazing of 5A06 aluminum alloy to SUS321 stainless steel has been carried out with Al-Si12 eutectic filler metal and modified non-corrosive flux. The surface appearance and microstructures of the joint were analyzed and the average tensile strength of the joint was estimated. The results show that a sound dissimilar metals joint is obtained by TIG welding-brazing. Slag and residual flux on steel surface can be removed by sanding easily. The joint has dual characteristics: in aluminum alloy side, it is a welded joint, while in stainless steel side, it is a brazed joint. The whole interface layer, unequal in thickness at different position, ranges from 5μm to 25μm. The average tensile strength of the butt joint reaches 120MPa and the fracture occurs at the interface layer.