Corrosion properties and contact resistance of TiN, TiAlN and CrN coatings in simulated proton exchange membrane fuel cell environments
Corrosion properties and contact resistance of TiN, TiAlN and CrN coatings in simulated proton exchange membrane fuel cell environments
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DOI：
10.1016/j.jpowsour.2009.12.127
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发表时间：
2010-06
影响因子：
9.2
通讯作者：
L. Wang;D. Northwood;X. Nie;J. Housden;E. Spain;A. Leyland;A. Matthews
中科院分区：
文献类型：
--
作者：
L. Wang;D. Northwood;X. Nie;J. Housden;E. Spain;A. Leyland;A. Matthews
在这项研究中，TiN，CrN和TiAlN电子束物理气相沉积（EBPVD）涂层及其不锈钢316L（SS 316L）基板的接触电阻（CR）和电化学性能进行了研究在模拟质子交换膜（PEM）燃料电池环境。动电位极化腐蚀试验在70°C下在1 M H2SO 4中进行，用O2或H2吹扫，恒电位腐蚀试验在模拟阴极（+0.6V vs. Ag/AgCl参比电极，用O2吹扫）和阳极条件（-0.1V vs. Ag/AgCl参比电极，用H2吹扫）下进行长时间（4 h）。用扫描电镜观察了腐蚀后试样的表面形貌。所有TiN-、TiAlN-和CrN-涂覆的SS 316L显示出比未涂覆的SS 316L更低的CR。虽然涂层的腐蚀性能取决于阴极和阳极条件，但CrN涂层表现出比未涂覆的SS 316L更高（在阳极环境中）或相似（在阴极环境中）的耐腐蚀性。因此，CrN涂层的SS 316L可以潜在地用作PEM燃料电池环境中的双极板材料。虽然EBPVD工艺与其他等离子体增强反应蒸发相比大大减少了涂层中的针孔数量，但未来的研究工作应致力于消除涂层中的针孔，以确保燃料电池应用的长期耐用性。
In this study, the contact resistance (CR) and electrochemical properties of TiN, CrN and TiAlN electron beam physical vapor deposition (EBPVD) coatings and their stainless steel 316L (SS316L) substrate were investigated in a simulated proton exchange membrane (PEM) fuel cell environment. The potentiodynamic polarization corrosion tests were conducted at 70°C in 1M H2SO4purged with either O2or H2, and the potentiostatic corrosion tests were performed under both simulated cathodic (+0.6V vs. Ag/AgCl reference electrode purged with O2) and anodic conditions (−0.1V vs. Ag/AgCl reference electrode purged with H2) for a long period (4h). SEM was used to observe the surface morphologies of the samples after corrosion testing. All the TiN-, TiAlN- and CrN-coated SS316L showed a lower CR than the uncoated SS316L. While the corrosion performance of the coatings was dependent on the cathodic and anodic conditions, the CrN coating exhibited a higher (in the anodic environment) or similar (in the cathodic environment) corrosion resistance to the uncoated SS316L. Thus, the CrN-coated SS316L could potentially be used as a bipolar plate material in the PEM fuel cell environment. Although the EBPVD process greatly reduced number of pinholes in the coatings compared to other plasma enhanced reactive evaporations, future research efforts should be directed to eliminate the pinholes in the coatings for long-term durability in fuel cell applications.