Microstructure and Wear Resistance of TiC Reinforced Co-Based Composite Coatings Modified with Nano-Sm₂O₃ by Laser Cladding

Nano-Sm₂O₃ particles reinforced TiC/Co-based composite coatings were prepared on 45 steel by laser cladding. The effect of nano-Sm₂O₃ particles on the microstructure and wear resistance of TiC/Co-based composite coatings was investigated systematically. The results showed that the phase constitute of nano-Sm₂O₃ particles reinforced TiC/Co-based composite coatings was composed of γ-Co, Cr₂₃C₆, TiC, Co₃Ti, Cr₃C₂ and Fe₇Sm, and the composite coatings showed better metallurgical bonding with the substrate, better spreadability, finer grains and more uniform microstructure in compared with coatings without nano-Sm₂O₃ particles. With the increase of nano-Sm₂O₃ addition, the microhardness and wear resistance of TiC/Co-based composite coatings were both first enhanced and then reduced, and the microhardness and wear resistance were respectively improved by 10.10% and 17.14%, for 1.5% nano-Sm₂O₃ addition. The wear mechanism of the composite coatings was abrasive wear. A significant influence of nano-Sm₂O₃ on the TiC reinforced Co-based composite coatings was confirmed by the results of applied multivariate statistical analysis.