Microstructure and Technology Research of In-situ Synthesis TiN- TiB2/Ni Composite Coating by Argon Arc Cladding

An in situ synthesis method was developed to produce an Ni alloy composite coating reinforced by in situ reacted TiN and TiB2 particles, using argon arc cladding (AAC) with different mass fractions of Ni60 and Ti+BN powders on a 16Mn steel substrate.The microstructure, micro-hardness and wear resistance were investigated using SEM, XRD, Micro-hardness Tester, and Friction and Wear Tester, respectively. The result showed that the main phases of coating were TiN, TiB2 (Fe,Cr)23C6 and γ-Ni.Excellent bonding between the coating and the 16Mn steel substrate is uniform, continuous and almost defect-free and the particles were gradient distributed in the clad coating. The microstructure is different from the outside to the inside in the clad coating. The microhardness showed a gradient variation, with the highest value of 1400HV0.2 and the wear properties of the coating are also improved at the room temperature under normal atmosphere conditions.