Corrosion Resistance and Wear Behavior of Ni60/TiC and NbC Composite Coatings Prepared by Laser Cladding

This research delves into the corrosion resistance and wear behavior of Ni60-based composite coatings strengthened by TiC and NbC particles, which are produced by laser cladding. Three distinct coatings were prepared: S1 (Ni60 + 20%TiC), S2 (Ni60 + 10%TiC + 10%NbC), and S3 (Ni60 + 20%NbC). Microstructural characterization revealed that the addition of TiC and NbC altered phase composition, inducing lattice distortion and promoting the formation of carbides such as Cr₇C₃, Ni₃C, and Nb₂C. The S2 coating exhibited the highest average microhardness (1045 HV) due to synergistic grain refinement and homogeneous carbide dispersion. Wear resistance followed the order S2 > S3 > S1, attributed to the optimized balance of hard-phase distribution and reduced abrasive wear. Electrochemical tests in 3.5 wt% NaCl solution demonstrated superior corrosion resistance for S3, characterized by the lowest corrosion current density (1.732 × 10^-6 A/cm²) and a stable passivation film, facilitated by NbC-induced oxide formation. While S2 achieved peak mechanical performance, S3 excelled in corrosion resistance, highlighting the trade-off between carbide reinforcement and electrochemical stability. This work underscores the potential of tailoring dual-carbide systems in Ni60 coatings to enhance durability in harsh environments.