Microstructure and Friction and Wear Performance of Ni35 Alloy Laser-Cladding Layer Reinforced by Ni-Coated SiC_p

Ni-coated SiC_p reinforced Ni35 alloy laser-cladding layer was prepared on surface of H13 die steel substrate by laser cladding technique. The microstructure and the friction and wear performance at 25, 600℃ of the cladding layer were studied. The results show that the cladding layer was composed of γ-Ni(Fe)+M₃(B, Si) eutectic phase, M₂₃C₆ carbide, M₇C₃ carbide, Ni₃₁Si₁₂ nickel-silicide, and graphite. After friction and wear at different temperatures, the cladding layer had a higher surface microhardness and a lower wear volume than the substrate. The wear resistance at 25℃ of the cladding layer was improved greatly comparing with that of the substrate, and the improvement effect was higher than that at 600℃. The wear mechanism at 25℃ of the cladding layer was mainly micro-abrasive wear and adhesive wear, while that at 600℃ was abrasive wear, adhesive wear and slight oxidation wear.