Effect of Laser-Induced N2 Gas and Ti6Al4V/Cr3C2 Powders Coupling on Properties of Composite Coatings with Ceramic Reinforcement Phases by In Situ Synthesis on Ti6Al4V

To break through the bottleneck of crack suppression in laser-fabricated high-hardness coatings, improving the wear resistance, the composite coating with ceramic reinforcement phases was in situ prepared on Ti6Al4V by laser-induced N₂ gas and Ti6Al4V/Cr₃C₂ powders. The results demonstrated that under a laser power of 1100 W and a scanning speed of 7 mm/s, a crack-free coating with a maximum hardness of 1119.72 HV was successfully fabricated. Cr₃C₂ powders were melted and N₂ was ionized by high-energy laser to in situ synthesize TiC, TiN, and CrN. The 10 wt.% Cr₃C₂ coating exhibited a bilayer structure with an isometric TiC layer above a granular TiN layer and the best performance in wear resistance with the wear rate of 2.62 × 10⁻⁸ cm³/N·m due to the TiC as a better support skeleton for the oxide film. The abrasive wear and oxidation wear were the wear mechanism.