Effects of SiC ceramic particles on microstructures and mechanical properties of gas tungsten arc welded AZ31 magnesium alloy with Cr2O3 flux coating

The effects of SiC ceramic particles on the macromorphologies, microstructures and mechanical properties of tungsten inert gas welded AZ31 magnesium alloy joints with Cr2O3 flux coating were investigated. The results showed that an increase in the amount of SiC ceramic particles contained in the Cr2O3 flux coating led to the gradual decrease in weld penetrations. The weld penetrations of all welded seams with flux coatings were obviously higher than those without flux coating. Grain refinement was obtained in the welded seams when SiC ceramic particles were added in the Cr2O3 flux coating. With an increase in the amount of SiC ceramic particles, the ultimate tensile strength value of the welded joints increased at first and then decreased. Moreover, the microhardness of the fusion zone increased gradually with an increase in the addition of SiC ceramic particles in the Cr2O3 flux coating.