Dissimilar Welding of Magnesium Alloys and Aluminum Alloys by Explosive Welding

Welding of dissimilar magnesium alloys and aluminum alloys is challenging due to the formation of interlayers composed of brittle intermetallic compounds (IMCs) at the bonding interface, which reduces the bonding strength. In our studies, we applied explosive welding to facilitate dissimilar welding of magnesium alloys and aluminum alloys. This method utilized a high-speed impact from an explosive to bond magnesium alloys and aluminum alloys in a short time, effectively suppressing the formation of the interlayer. Our research confirmed the presence of a thin interlayer of the γ-Mg₁₇Al₁₂ phase at the interface of the cladding plates. The alloy compositions of both magnesium alloys and aluminum alloys influenced the thickness of this interlayer. Furthermore, annealing of the cladding plates increased the thickness of the interlayer, resulting in the formation of the aluminum-rich β-Al₃Mg₂ phase on the aluminum alloy side after annealing at 473 K. The formation of the brittle β-Al₃Mg₂ phase led to crack initiation, which reduced the shear strength. In terms of corrosion resistance, the corrosion weight loss of the explosively welded cladding plates was slightly less than that of mechanically fastened samples. Therefore, it can be concluded that explosive welding is highly effective for bonding magnesium alloys to aluminum alloys.