In Situ Generation of TiCN Ni‐Based Coatings by Laser Cladding and Study of Their Structure and Properties

Abstract

The influence of the ratio of TiN powder, graphite powder, and Ni60 powder on the phase composition, microstructure, microhardness, and wear properties of the TiCN Ni‐based coating on H13 steel is investigated. The findings indicate that varying proportions of TiN powder, C powder, and Ni60 powder have a minimal impact on the coating's phase composition. The diffraction peak intensity of TiC0.3N0.7 increases with the addition of (C + TiN) in the blended powder, while the crystallinity of TiC0.3N0.7 in the Ni‐based coating with a 30% (C + TiN) mass fraction decreases. The grain structure of the 20% Ni‐based coating is fine and uniform, while the microstructure of the 30% Ni‐based coating is characterized by a large polymerization phase‐containing Ti elements, with the TiCN‐reinforced phase exhibiting irregular grain morphology. The microhardness HV0.5 of the coating with a 20% (C + TiN) mass fraction ranges from 725 to 772, with an average hardness of 747.8 HV0.5, which is 3.4 times the hardness of the substrate material and 1.3 times the hardness of the Ni‐based coating. As the mass fraction of (C + TiN) in the hybrid powder increases, the friction loss mass of the coating tends to decrease and then increase. The average wear of the Ni‐based coating with a 20% (C + TiN) mass fraction is ≈22.4% of that of the substrate and 50% of that of the Ni‐based coating, demonstrating excellent wear resistance. The wear mechanism is primarily characterized by brittle spalling and abrasive wear.