Multi-Objective Process Optimization and Properties of Ti(C,N) Ceramic Coatings Prepared By Laser Cladding
摘要
Ceramic coating prepared by laser cladding is an effective methods for enhancing the surface properties of materials, where the process parameters directly influence the quality characteristics of the coating formation. To investigate the effects of the process parameters on the quality characteristics of Ti(C,N) ceramic coatings prepared by laser cladding on the Ti6Al4V substrate, a mathematical model was developed to establish the relationship between the process parameters (laser power, scanning speed, and overlapping ratio) and the quality characteristics (thickness, width, and microhardness) using the response surface methodology. Additionally, the optimal process parameters were determined through multi-objective optimization using the overall desirability function. Finally, the microstructure and properties of Ti(C,N) ceramic coatings prepared by laser cladding under optimized process conditions were further analyzed. The results showed that the mathematical model linking the process parameters to the quality characteristics exhibited high predictive reliability. The laser power and overlap rate were the crucial process parameters for the quality characteristics of Ti (C, N) ceramic coatings. The optimal process parameters based on the multi-objective optimization were as follows: laser power of 853.09 W, scanning speed of 8.18 mm/s, and an overlap rate of 40%. The Ti(C,N) ceramic coating prepared by laser cladding comprised TiC0.3N0.7 with equiaxed grains, Ti3Al intermetallics, and α-Ti. The microhardness and wear volume of the coating were 1064.87 HV0.2 and 4.44 × 106 μm3, respectively. Its friction coefficient decreased by 56.97% compared to the substrate. The wear mechanisms of the coating were slightly abrasive wear and oxidative wear. The tribological properties of the Ti6Al4V substrate surface were significantly improved by the TiC coatings. This work advances the research on the process parameters of the high-quality ceramic coatings prepared by laser cladding.