Resistance spot weld fatigue behavior and dislocation substructures in two different heats of AZ31 magnesium alloy

Fatigue life and dislocation substructure were evaluated in two groups of AZ31 Mg alloy resistance spot welds (heats SA and SB respectively, which had similar chemical compositions but different fusion zone microstructures). The results showed that the SA welds with a refined microstructure displayed a higher fatigue resistance than the SB welds when tested under conditions of higher cyclic load range causing interfacial failure across the …