Investigation into the tribocorrosion behavior of laser cladding titanium matrix composite coatings with Y₂O₃ addition

Y₂O₃-modified titanium-based composite coatings were fabricated on Ti6Al4V alloy via coaxial powder feeding laser cladding. The influence of Y₂O₃ addition on the microstructure and tribocorrosion properties was systematically investigated. The results indicate that coatings with different Y₂O₃ contents consist of a β-Ti matrix, TiC reinforcing phase, and other phases such as Ti₂Ni, Ti₂S and TiS₃. Compared with the coating without Y₂O₃, the microstructure of the coating with 4 wt% Y₂O₃ was significantly refined, with coarse dendrites transforming into fine particles. Tribocorrosion tests in 3.5 wt% NaCl solution showed that the volumetric wear rate of the modified coating was reduced by 74.3% and 50.0% compared to the substrate and the unmodified coating, respectively. First-principles calculations revealed that the low surface energy of TiS₃ and the high work function of TiC synergistically enhance the anti-adhesion and corrosion resistance of the coatings.