石墨烯添加剂在微弧氧化层中作用机理

Effects and Mechanisms of Graphene Additive in Micro-arc Oxidation Composite Coatings

微弧氧化是轻合金表面防腐的关键手段,复合涂层中石墨烯的防腐减摩潜能也被逐渐挖掘验证。详细介绍了石墨烯添加剂对电解液和电参数,以及膜层结构和性能等方面影响作用的研究现状,阐述轻合金表面石墨烯复合微弧氧化层需要进一步探索的问题。电解液中添加石墨烯后,降低了阳极绝缘层击穿电压,促进了膜层的生长和新相生成;微弧氧化层中石墨烯以填充和包覆的增强相形式存在,可明显改善膜层的致密度和厚度,促进膜层防腐耐磨性能进一步提升;结合轻合金表面碳元素、相位角和阻抗等特征参数的表征分析,可以较好地验证滑动摩擦和电化学腐蚀过程中石墨烯的增强作用机理,绘制的原理示意图也更具直观性。

As a key surface treatment technology for light alloy,micro-arc oxidation(MAO)could effectively improve its anticorrosion performance.The graphene additive has been recognized in the method of MAO gradually and used for enhancing film’s anticorrosion and antifriction properties.In this paper,it was expounded for the research status about the graphene effects on the process parameters of electrolyte and electricity,and the structure and properties of MAO film.Meanwhile,it was indicated that its deepening research direction.In general,by the way of adding graphene in electrolyte,it could decrease the breakdown voltage of oxide film on the surface of anodize,and promote the oxide film growth and the new phase formation composited of oxide film.The graphene embedded in the form of filling and coating,and could enhance film’s microstructure and properties,including the intensity,thickness,antifriction and anticorrosion.With analyzing the characterization of the carbon existence,phase angle,impedance,and vivid schematic diagrams by modern analytical testing techniques,it could be well perceived for the strengthening mechanism of graphene composite MAO film in the processes of sliding friction and electrochemical corrosion.