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采用等离子喷涂技术在304不锈钢表面沉积Ti N涂层,研究其在燃料电池环境中的腐蚀和导电性能。采用XRD和SEM对涂层组织结构和微观形貌进行了表征,通过动电位极化曲线、电化学阻抗谱技术比较了涂层与基体在模拟电池环境中(0.3 mol/L H_2SO_4+2 mg/L HF)的耐蚀性,并测定了接触电阻。结果表明:涂层的自腐蚀电位显著高于基体的,且腐蚀电流密度下降近1个数量级,这与所制备厚约20μm涂层的均匀致密性有关。在360 h浸泡过程中,涂层的开路电位显著高于基体,稳定性良好,虽阻抗随时间有所降低,但仍维持较高值,涂层能够对基体提供有效保护。在138 N·cm-2压力下,Ti N涂层的接触电阻为50 mΩ·cm-2,低于基体的,表现出更优越的导电性能。
TiN coating was deposited on the surface of 304 stainless steel by plasma spray technique to study its corrosion and electrical conductivity in the fuel cell environment. The microstructure and morphology of the coating were characterized by XRD and SEM. The coating and matrix were compared in a simulated cell environment (0.3 mol / L H 2 SO 4 + 2 mg / L) by potentiodynamic polarization curves and electrochemical impedance spectroscopy L HF) corrosion resistance, and measured the contact resistance. The results show that the corrosion potential of the coating is significantly higher than that of the matrix, and the corrosion current density decreases by nearly one order of magnitude, which is related to the uniform compactness of the prepared coating about 20μm thick. In the 360 h immersion process, the open circuit potential of the coating was significantly higher than that of the matrix, and the stability was good. Although the impedance decreased with time, it maintained a high value and the coating provided effective protection to the substrate. At a pressure of 138 N · cm -2, the contact resistance of the Ti N coating is 50 mΩ · cm -2, which is lower than that of the matrix and shows superior electrical conductivity.