| Ni/Al2O3 is the best candidate for corrosion and wear resistance materials because of their high hardness, good chemical resistance and lower cost. In this study,N i/Al2O3 composite coating was prepared by electro-co-deposition and flame spraying respectively and the influence of raw materials on formation and coating structure were studied as well.Different types of surfactants were added into Watt bath for electro-co-deposition to study the influence on the formation of the composite coatings and the deposition of Al2O3 particles. The dispersibility and adsorption of Al2O3 particles were evaluated by particle size, sediment, ?-potential measurement and FTIR. Morphology and composition of coatings were characterized by SEM-EDS for inferring the influence and the involved mechanisms of coating’s structure by addition of the surfactants.Raw and coated Al2O3 particles mixed with N i powers were used to prepare the composite coatings by flame spraying. The optimum spraying parameters of the spraying process were obtained through SEM analysis and mechanical test. The relationship between the powders and the coatings were discussed as well. It is indicated that the coated Al2O3 particles can improve the structure and properties o the composite coatings compared to uncoated Al2O3 particles and the hardness was increased by about 24.43%.Flame sprayed N i/Al2O3 composite coating has poorer properties compared to electro-co-deposited coatings because more flaws are presented in the coatings. |
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