Method for forming composite layer by laser irradiation upon aluminum alloy substrate surface of powder mixture containing metal carbide ceramic particles, silicon, and metal element forming inter metallic compound with silicon

摘要

In a method for forming a covering composite layer on the surface of an aluminum alloy substrate, a powder mixture containing ceramic carbide of a metal, silicon and a metal element which forms with silicon an inter metallic compound having a specific gravity comparable with that of the ceramic carbide is disposed upon the surface of the aluminum alloy substrate, and then the powder mixture so disposed is irradiated with a laser, so that the silicon and the metal element which forms the inter metallic compound with silicon in the powder mixture and a surface portion of the aluminum alloy substrate are melted and fused together. The silicon expedites uniform distribution of the ceramic carbide particles in a molten surface layer of the aluminum alloy substrate by producing a melt of the inter metallic compound having a specific gravity comparable with the ceramic carbide, thereby preventing segregation of the ceramic carbide particles due to specific gravity difference, while highly uniformly dispersing the ceramic carbide particles are carried by the inter metallic compound having affinity toward the aluminum alloy due to silicon component.