Microstructure And Oxidation Performance Of Tic-Mosi2 Reinforced Composite Coating Prepared By Plasma Transferred Arc Cladding

In order to improve the oxidation resistance and wear properties of AISI 304, a TiC-MoSi2 complex phase enhanced composite coating was designed and in-situ prepared on AISI 304 substrate by plasma transferred arc (PTA) cladding technique. Microstructure of the composite coating before and after oxidation was analyzed. The hardness distribution of the coating was tested. The oxidation kinetics curves of the coating were measured and fitted. The oxidation mechanism of the coating was discussed. Results show that typical microstructure of the composite coating consists of TiC-MoSi2 complex phases, primary TiC dendrites and gamma-(Ni, Fe)/NiSi2 eutectics. The TiC-MoSi2 complex phases and TiC dendrites as reinforcing phases are uniformly distributed on the gamma-(Ni, Fe)/NiSi2 eutectic matrix. Due to the strengthening effect of the TiC-MoSi2 complex phases and the binding and supporting action of the ultrafine gamma-(Ni,Fe)/NiSi2 eutectic matrix, the composite coating exhibits high and uniform hardness distribution, good strength and toughness. Thanks to its unique microstructure, the composite coating shows good oxidation resistance.