Modification of thermally sprayed cemented carbide layer by friction stir processing

The modification of a thermally sprayed cemented carbide (WC–CrC–Ni) layer by friction stir processing (FSP) was studied. The cemented carbide layer was successfully modified using a sintered cemented carbide (WC–Co) tool. The defects in the cemented carbide layer disappeared and the hardness of the cemented carbide layer increased to ∼ 2000 HV, which was about 1.5 times higher than that of the as-sprayed cemented carbide layer. Additionally, the cemented carbide layer was bonded to the SKD61 (Nominal composition: 0.35–0.42 mass% C, 0.8–1.2 mass% Si, 0.25–0.5 mass% Mn, 4.8–5.5 mass% Cr, 1.0–1.5 mass% Mo, 0.8–1.2 mass% V, balance Fe) substrate by diffusion of the metallic elements and the distortion of the coating–substrate interface producing a mechanical interlocking effect.