Strength and structure of the bonding interface in friction-welded 1050 aluminum and AZ31 magnesium alloy joint

Abstract

Bonding interfaces of friction-welded 1050 aluminum/AZ31 magnesium alloy joints, before and after annealing at 673K for 1h, were examined by tensile test for bonding strength, by optical micrography, EPMA and X-ray analysis for phases in the interfacial reaction. Bonding strength of the friction-welded joints in the as-welded state was dependent on the thickness of interfacial reaction layer. The thinner layer had resulted in the higher bonding strength (about 45MPa). The interfacial reaction layer consisted of two sublayers of compounds (Al₃Mg₂ and Al₁₂Mg₁₇). The former compound predominantly grew by the annealing. That fact resulted in the brittlement of the interface.