Effects of fluxes on distribution of SiC particles and microstructures and mechanical properties of nanoparticles strengthening ATIG (NSA-TIG) welded magnesium alloy joints

摘要

The effects of fluxes and the size of SiC particles on the morphologies, microstructures andnmechanical properties of tungsten inert gas welded AZ31 magnesium alloy joints wereninvestigated. The results showed that addition of SiC particles in the activating fluxes led to thendecrease in all the weld penetrations while the surface appearance of welded joints improved innthe case of TiO2 activating flux was adopted. Grain refinement was obtained in the welded seamsnwith the addition of SiC particles in TiO2 flux and the effect of nanosized SiC particles on grainnrefinement is found to be more impressive than that of microsized SiC particles. Thenmicrohardness of the fusion zone and ultimate tensile strength of the welded joints increasednwith the addition of SiC particles in TiO2 activating flux and nanosized particles have more strongnefficiency on the improvement of mechanical properties compared with microsized SiC particles.nSiC particles did not improve the mechanical properties of A-TIG welded joints with CaF2nactivating flux.