等离子喷涂碳阴极TiB_2涂层

Carbon Cathode TiB_2 Coatings by Plasma Spraying

采用等离子喷涂法制备碳阴极TiB2涂层,运用XRD、SEM分析测试手段对涂层的形貌、组织和物相成分进行表征,并对涂层孔隙率、结合强度及其电阻率进行分析测试。结果表明,涂层中有部分未完全熔融粒子,涂层存在孔隙,孔隙率为7.15%,较一般等离子喷涂的孔隙率（3%～8%）偏大;涂层与基体结合紧密,具有良好的结合强度（36.5 MPa）;粒子喷涂时部分TiB2被氧化成TiO2和B2O3,而B2O3会吸收空气中的水分形成H2BO3;电阻率随温度的升高而减小。

Carbon cathode TiB2 coating was prepared by plasma spraying, and its morphology, microstructure, and phase composition were characterized by XRD and SEM. Further, the porosity, bonding strength and resistance of the coating were tested and analyzed. The results show that some particles are note completely melted and pores exist in the coatings, and its porosity of 7.15% compared with normal plasma spraying porosity（3%-8%） is too large. However, the coatings adhere well to the substrate, and have good bonding strength. Portion of TiB2 particles are oxidized into TiO2 and B2O3, and B2O3 will absorb moisture from the air to transform into H2BO3; the resistivity decreases with temperature increasing.