高能微弧合金化沉积氮化物陶瓷覆盖层及其耐蚀性能分析

采用高能微弧合金化技术沉积TiCN冶金结合涂层,用于金属双极板的表面防护。沉积过程中的参数,如输出电压、功率、频率、气流量等对沉积层耐蚀性的影响较大。随着功率增加,TiCN涂层在304不锈钢基体上的沉积圈半径由小变大,且对应酸性溶液中腐蚀电流密度随功率的增大而减小;随频率的增加,单点脉冲放电能量是呈减小的趋势,且腐蚀电流密度随频率的增大而增大,这与沉积过程中的输出能量相关。

Corrosion Behavior and Structure Characterization of Nitride Ceramic Coatings Prepared by High Energy Micro-arc Alloying Procedure

Disadvantages of the present candidate metallic materials for bipolar plate are low corrosion resistance and high contact resistance in acidic environment for an extended period of time that can cause power degradation or cell failure. Therefore, great attempts are conducted to improve the corrosion resistance of metals while keeping low contact resistance. In the present study a high-energy micro-arc alloying process is adopted to prepare a TiCN coating on 304 stainless steel bipolar plates with a metallurgical bonding between the coating and substrate. The corrosion characteristics of TiCN coatings are seriously affected by deposition parameters such as output voltage, power, frequency, and flow rate of gas. The results showed that with the increasing power, the diameter of the deposited circles of TiCN increased while the corrosion current density of the coating decreased; with the increasing frequency and the decreasing pulse energy for a single deposited spot, the corrosion current density of the coating increased. The effect of deposition parameters on corrosion behavior of TiCN coatings is also discussed in detail.