Preparation And Investigation On Microstructure And Properties Of Wear Resistance Coating For Turbine Impeller

At present, the NiTi alloy has been widely used in aerospace, aviation, machineryindustry to improve the wear resistance and corrosion resistance of the equipment as aresult of its good chemical stability, wear resistance and corrosion resistance. Based on themicrostructure of turbine impeller should have high stability, good corrosion resistance anderosion resistance as well as economic considerations, this research on preparation andinvestigation on microstructure and properties of wear resistance coating for turbineimpeller has high theoretical value and application prospect.NiTi coating, NiTi/Ni composite coating and NiTi/NiAl composite coating wereprepared on0Cr13Ni5Mo stainless steel substrate by supersonic arc spraying. The phasecomposition and surface morphologies were compared analyzed by scanning electronmicroscope and X ray diffraction. Bonding strength test and micro-hardness test were done.Erosion wear test and cavitation erosion test were finished by erosion tester and ultrasonicstretching vibration cavitation test machine. The performance on erosion wear resistanceand cavitation erosion resistance of the three kinds of coating were compared.The results show that the three kinds of coating are well bonding with substrate andthe microstructures are dense. The oxidation resistance of NiTi/Ni composite coating andNiTi/NiAl composite coating are better than NiTi coating. NiTi/NiAl composite coatinghas the highest micro-hardness and NiTi/Ni composite coating has the lowestmicro-hardness. In terms of erosion wear resistance, with the increasing of erosion angle,the quality of cumulative losses of NiTi/Ni composite coating is the minimum and thequality of cumulative losses of NiTi/NiTi coating is the most. In terms of cavitation erosionresistance, the quality of cumulative losses of NiTi/Ni composite coating is much higherthan that of other two coatings. Above of all, the oxidation resistance and comprehensiveperformance of NiTi/NiAl composite coating have a certain advantage than other twokinds of coating.