Research on Microstructure and Wear Resistance of In-situ Synthesized Multiphase Ceramics Reinforced Fe-based Composite Coatings by Laser Cladding

To improve the wear resistance of titanium alloy surface, Fe60 self-melting alloy powder was mixed with B₄C, TiN, and Y₂O₃ ceramic powders as preplaced materials, and in-situ synthesized multiphase ceramic reinforced Fe-based composite coatings were prepared by laser cladding on the surface of Ti6Al4V substrate. The microstructure, phase composition, and wear resistance of the coatings by laser cladding under different scanning speeds were investigated using analysis methods such as scanning electron microscopy, X-ray diffraction, and friction testing machine. The results indicate that the coating is mainly composed of in-situ synthesized rod-like TiB₂, dendritic TiC, granular TiC_0.7N_0.3, and Fe under the conditions of laser rapid remelting and solidification. Fe-based composite coatings without obvious cracks can be obtained by laser cladding at a scanning speed of 3 mm/s, and its hardness and wear resistance are 2.8 times and 2.0 times than that of the substrate, respectively. The wear mechanism of the coating is abrasive wear and adhesive wear. In-situ synthesis multiphase ceramic reinforced Fe-based composite coatings fabricated by laser cladding can significantly improve the wear resistance of titanium alloy surfaces.