阴极等离子电解氧化(CPEO)打破等离子体电解领域传统认识，利用液相放电现象，使钢铁及钛基材料阴极表面快速氧化，是一种氧化膜制备新方法，提高了材料的耐磨、耐蚀性能。与微弧氧化或阳极等离子电解氧化技术相比，CPEO技术的氧化膜生长速率显著提高，并适用于各种钢铁材料表面改性。介绍了CPEO技术的基本原理，包括液相放电现象和电压电流的演变过程、气膜形成与击穿过程、阴极内部近表面温度随电压变化规律和快速氧化过程，并对比分析了CPEO与阳极等离子体电解氧化和电解渗技术原理的共性与差异。介绍了光发射谱测量和等离子体参数的计算结果，分析阴极等离子体放电环境中阴极等离子体电解氧化机制。进一步总结了碳钢、不锈钢、Mo、TiAl合金表面CPEO膜的形貌、组织结构和性能特点，分析电解液中悬浮的碳粉特性，探讨放电过程中类金刚石(DLC)成分合成的可行性，并初步制备出含DLC成分的CPEO复合氧化膜。最后总结并展望了CPEO技术的发展方向以及应用前景。

Cathodic plasma electrolytic oxidation (CPEO) is a novel oxide coating fabrication technology developed on the basis of plasma electrolysis in liquid. The Fe-based and Ti-based metal cathodes can be quickly oxidized under liquid phase discharge, which improves their wear resistance and corrosion resistance. It is believed that the CPEO technology is a breakdown for conventional knowledge in the plasma electrolysis field. Compared with anodic plasma electrolytic oxidation, namely microarc oxidation, the CPEO technique has much high growth rate of oxide coating and meanwhile it may be also applied to the surface modification of all kinds of Fe-based materials. The basic principle of CPEO technique was introduced, including the evolution of liquid phase discharge phenomenon, voltage and current, the formation and breakdown process of vapor gas envelope (VGE), the near-surface temperature in the cathode under different voltages and the rapid oxidation process of cathode. Furthermore, the similarity and difference among the CPEO technology and anodic plasma electrolytic oxidation and plasma electrolytic saturation were compared. In addition, the detection of optical emission spectroscopy during the CPEO discharge process and the corresponding calculation of plasma parameters such as plasma electron density and electron temperature were also introduced, and then the growth mechanism of CPEO oxide coatings at cathodic discharge environment was discussed. On the other hand, the morphology, microstructure and properties of CPEO coatings on metals such as low-carbon steel, high-carbon steel, stainless steel, molybdenum and TiAl alloys were summarized. The carbon particle property suspended in electrolyte solution was analyzed, and the possibility for synthesis of diamond-like carbon component during VGE discharge process was discussed. It was found that the DLC-containing CPEO composite coatings on metals could be fabricated under liquid phase discharge in glycerin and urea solutions. Finally, the development direction and potential application of cathodic plasma electrolytic oxidation technology were summarized and prospected.