Research on TIG welding of He-Ar mixed gas for SiCp/6061 Al composite

Taking the He-Ar mixed gas as protected atmosphere,the TIG welding with filter wire for SiCp/6061 Al composites were investigasted in this paper.When the current,gas-flow rate and welding speed of He-Ar mixed gas are 60 A,115 mL/s and 3.2 mm/s,respectively,the good quality weld joint is obtained.The microstructure examined have shown that the microstructures in welded seam zone consist of finer exquiaxed grains,while the microstructure in heat-affected area is coarser than that in matrix zone.The tensile strength of the welded joint is about 70% of the matrix.The breaking point lies in the heat-affected zone and the mixed fracture of toughness and brittleness was observed.