Si-DLC薄膜在硝酸介质中的腐蚀磨损行为与机理

Corrosion-Wear Mechanism of Si-DLC Films in Nitric Acid Solution

本文中利用电化学工作站与摩擦试验机研究了DLC薄膜与Si-DLC薄膜在去离子水和硝酸环境下的腐蚀摩擦行为,并通过动电位极化和电化学交流阻抗测试研究了两种薄膜的电化学腐蚀性能,结合磨损试验结果综合分析了两种薄膜在硝酸环境下的腐蚀磨损机理.结果表明:Si掺杂增加了薄膜在硝酸环境下的腐蚀电流密度;减小了DLC薄膜在去离子水和硝酸环境下的摩擦系数;磨损结果分析发现机械磨损是造成薄膜损伤的最主要因素,腐蚀-磨损的相互作用约占薄膜总磨损量的4%,其影响作用不可忽视.

In this study, tribocorrosion behaviors of DLC and Si-DLC films in deionized water and nitric acid environment were investigated by the electrochemical workstation and tribometer. The potentiodynamic polarization and electrochemical impedance spectroscopy tests were performed to evaluate the electrochemical property of the two films.The wear volumes in different environments were used to investigate the corrosion-wear mechanism of DLC and SiDLC films in nitric acid solution. The results indicate that doping of Si element in DLC films decreased the friction coefficient, while it also led to deterioration of corrosion protection property, due to the increasing corrosion current density of films in nitric acid solution. Corrosion-wear of films was determined mainly by mechanical wear and affected scarcely by electrochemical corrosion. The synergistic effect between mechanical action and electrochemical corrosion was also a significant factor during tribocorrosion, and accounted for nearly 4% of the total wear volume of DLC and SiDLC films.