Study of flux assisted TIG welding of magnesium alloy with SiC particles in flux

摘要

Activating flux assisted tungsten inert gas welding of magnesium alloy was investigated, and TiO2 powder mixed with SiC particles were selected as the flux. The results indicated that the penetrations with different percentages of SiC in the flux were almost the same, and that they were all higher than that without flux. It was shown that the SiC particles were distributed and dispersed in the weld bead, and particle content was higher in the centre of the weld than at the edge of the weld by the results of SEM and EDS. The mechanical properties of the weld beads were obviously improved by tensile tests and microhardness tests, when SiC was added in the flux TiO2. When flux 60%TiO2+40%SiC was used, the tensile strength of the weld bead reached 89·6% of base metal, and it was almost the same as that of the weld bead without any flux. The microhardness of the weld metal was nearly the same as the base metal. The reason of hardening of the weld bead with SiC in the weld metal was dispersion hardening.