Effect of Scanning Speed on Microstructure and Properties of Ni/B4C/TiC Coating

Ni/B4C/TiC coating was prepared using laser cladding technology with 45 steel as substrate material. The effects of different scanning speeds on phase composition, microstructure, microhardness, and tribological properties were investigated. It was found that the coating is primarily composed of Fe3B, Fe3C, B2Fe3Ni3, TiC, and solid solution of [Fe, Ni]. TiC particles are not completely dissolved, which promotes grain refinement. The microhardness increases with the increase in scanning speed and reaches the maximum value at 240 mm/min. The wear resistance test revealed that the coating exhibited the best wear resistance at 240 mm/min. The main wear mechanisms were fatigue wear, abrasive wear, and a small amount of oxidative wear.