Effect Of Hastelloy X Alloy On The Microstructure And High Temperature Oxidation Resistance Of Ti (c, N)-based Cermets

In this paper, Cermets especially Ti (C, N)-based cermets were reviewed, mainly study the effects of Hastelloy X powder (HXP) on the microstructure and oxidation of Ti (C, N)-based cermets, whose components is 32 % (Ni + HXP) -36.5% TiC-10% TiN-12.5% Mo-7.2% WC-1% Cr3C2-0.8% C. Use the optical microscope (OM), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and so on, three-point bending tests and high-temperature oxidation experiments to study the microcharacteristics and the microstructure of oxide film, mechanical properties and high temperature oxidation resistance of Ti (C, N)-based cermets.Both the relative density and the bending strength of Ti (C, N) -based cermets which have the same law follow parabolic law in line with the sintering temperature, and the two kinds of peaks are both at the best sintering temperature. The relative density of cermets with 5% HXP close to 98%, higher than that of cermets with 0% HXP, and the maximum bending strength of the former is closer to 2000MPa, which is higher than that of the latter, whose is 1848MPa, while the other cermets are lower, and the higher content of HXP, the lower peaks; The effect of HXP on hardness of Ti (C, N)-based cermets which are between 89.5-90.5HRA is not obvious.Ni-Cr-Fe solid solutions were found in the Ti (C, N)-based cermets with HXP, and the solid solution and its components are slightly different with the addition of HXP increase. All the Ti (C, N)-based cermets can basically form a core-shell structure, and most of the core-shell structures have the rim-phase. The microstructure of the Ti (C, N)-based cermets containing 0-16% HXP belong to the classical ceramic structure. The cermets containing 5% HXP and 0% HXP are almost with complete core-shell structure, and the thickness of rim-phase is slightly less than 0.5μm. Part of the microstructures of Ti (C, N)-based cermets contenting of 22% HXP are incomplete, and the thickness of a lot of the rim are more than 0.5μm. For 32% HXP, there are many holes in the material surface, and most of the microstructure is not complete and uneven.Oxide film growth rate of Ti (C, N)-based cermets follow the parabolic law. The kinetic equations of oxidation weight gain of were simulated. when the cermets content of 0% -10% HXP, the oxide films are relatively dense, a good high-temperature anti-oxidation, and while the oxide film of materials which content 5%HXP is more dense than non-HXP material, and combined with that the relative density of the former is higher than the latter, so the high-temperature oxidation resistance of the former is better than the latter; when Ti (C, N)-based cermets content more than 16% HXP, the oxide films are porous reducing the high-temperature antioxidant capacity.The high-temperature oxidation resistance of Ti (C, N)-based cermets should be increases with HXP, but the relative density of the high content of HXP was very low, which greatly reduces the high-temperature oxidation resistance. The high-temperature oxidation resistance of Ti (C, N)-based cermets which are contents of 5% HXP are the best by comprehensive analysis.