The effect of Zr addition on the laser welding of SiCp/2A14Al composite

Zr foil was applied in the laser welding of SiCp/2A14Al composites. The Al4C3 phase and pores was decreased in the fusion zone with Zr addition. The area of fusion zone decreased with the amount of Zr addition. Two new phases (Al3Zr and ZrC) were formed in the fusion zone with Zr addition. Al3Zr was strip-like. ZrC was polygonal particle. ZrC particles were formed around the SiC. The size of Al3Zr and ZrC was smaller than that of Al4C3. Only a thin layer of Al4C3 was formed on surface the SiC particles with Zr addition. The pores and pits left by Al4C3 hydration significantly decreased the hardness of fusion zone without Zr addition. The hardness of fusion zone increased with Zr addition. The tensile strength of welded joint increased from 105.6 MPa (without Zr addition) to 234.7 MPa (with 0.1 mm Zr foil). The mechanical strength of welded joints was significantly improved by Zr addition.