多弧离子镀TiN膜的腐蚀行为
(武汉理工大学 材料复合新技术国家重点实验室，武汉430070)
摘 要: 为了增强钛金属双极板的耐腐蚀性能，通过多弧离子镀膜技术在钛基双极板表面镀一层TiN，对薄膜的表面形貌，晶体结构与耐腐蚀性能之间的关系进行研究。结果表明：镀有TiN膜样品的耐腐蚀性能比未镀膜样品的有明显提高，其腐蚀电流密度最低可达201 μA/cm2。测试其动电位极化曲线和恒电位极化曲线发现，样品的耐腐蚀性能与薄膜的晶体结构以及表面颗粒和孔洞有密切的关系。适当的晶体择优取向有利于提高样品的耐腐蚀性能，而表面的颗粒和孔洞对样品的长期耐腐蚀性有很大影响。通过能谱分析发现，腐蚀后的样品表面发生了氧化。
关键字: 质子交换膜燃料电池；钛基双极板；多弧离子镀；耐腐蚀性；TiN膜
PEMFC by multi-arc ion plating
（State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,
Wuhan University of Technology, Wuhan 430070, China）
Abstract:In order to enhance the corrosion resistance of Ti bipolar plates, TiN films were deposited on titanium as bipolar plates for proton exchange membrane fuel cells (PEMFC) by adjusting the nitrogen pressure. The relationships among the surface morphology, crystal structure and corrosion resistance of the film were investigated. The results show that the TiN-coated titanium exhibits higher corrosion resistance than uncoated titanium, the lowest current density was 201 μA/cm2. Potentiodynamic and potentiostatic tests show that the corrosion resistance of TiN-coated sample is greatly associated with the crystal structure and particles and holes on the surface of the film. The suitable growth orientation is favorable to enhancing the corrosion resistance of TiN-coated samples. However, the particles and holes on the surface are bad for the long-time corrosion resistance of the sample. The energy dispersive spectroscopy (EDS) shows that the surface oxidation occurs on the surface of the sample after corrosion.
Key words: PEMFC; titanium bipolar plates; multi-arc ion plating; corrosion resistance; TiN film
