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采用大气等离子喷涂、爆炸喷涂和超音速火焰喷涂三种热喷涂技术制备了NiCr/Cr3C2-BaF2.CaF2涂层,分析比较了涂层的显微组织、物相组成、孔隙率、硬度、结合强度及其摩擦学性能。结果表明,与大气等离子喷涂相比,超音速火焰喷涂和爆炸喷涂技术制备的涂层具有更高的致密度、硬度和结合强度。采用包覆法制备的粉末进行喷涂,碳化物失碳明显减少,涂层中氧化物含量低。三种NiCr/Cr3C2-BaF2.CaF2热喷涂涂层的摩擦系数都随着温度的升高而减小,爆炸喷涂和超音速火焰喷涂涂层的摩擦系数比等离子喷涂涂层的摩擦系数更低,耐磨性得到提高。高温下BaF2.CaF2润滑膜的形成均可有效降低三种涂层的摩擦系数,从而降低涂层和对磨球Si3N4的磨损率。
The NiCr / Cr3C2-BaF2.CaF2 coatings were prepared by three kinds of thermal spray techniques, atmospheric plasma spraying, explosion spraying and supersonic flame spraying. The microstructure, phase composition, porosity, hardness and bonding strength And its tribological properties. The results show that coatings prepared by supersonic flame spraying and explosive spraying have higher density, hardness and bonding strength than atmospheric plasma spraying. The powder prepared by the coating method is sprayed, the loss of carbides is obviously reduced, and the oxide content in the coating is low. The friction coefficients of the three NiCr / Cr3C2-BaF2.CaF2 thermal sprayed coatings decrease with the increase of temperature, the friction coefficient of the explosive sprayed and supersonic flame sprayed coatings is lower than that of the plasma sprayed coatings, Wear resistance is improved. The formation of BaF2.CaF2 lubricating film at high temperature can effectively reduce the friction coefficient of the three coatings, thus reducing the wear rate of the coating and the ball Si3N4.