金属表面液相等离子体电解渗技术包括等离子体电解渗碳、渗氮、渗硼等。它具有渗透效率高、工作电压低、处理工艺简单、成本低等优点。主要介绍了钢铁、钛等金属表面等离子体电解渗硼技术的最新进展，分析了它的放电过程和基本原理，研究了渗硼过程的光发射谱，并评估了等离子体放电区的电子温度、电子浓度特征参数。分析了渗硼层的生长过程和形成机理，探讨了金属基体成分、工作电压、处理温度和电解液的组成等关键参数，对渗硼层的显微组织和相成分的影响。最后简要探讨了等离子体电解渗硼技术目前存在的问题和后续的发展方向。

Plasma electrolytic saturation technology on surface of metals includes plasma electrolytic carburizing, nitriding, boriding, etc. The technology takes advantages such as high processing efficiency, low applied voltage, simple treatment process and low cost. Here, the latest development of plasma electrolytic boriding (PEB) on the surface of steel, titanium and other metals was introduced. The discharge process and basic principle of PEB were analyzed. The optical emission spectrum in boriding process was detected, and the characteristic parameters of electron temperature and electron concentration in plasma discharge region were evaluated. The growth process and formation mechanism of boride layer were analyzed. The effects of some key parameters such as composition of metal substrate, applied voltage, treating temperature and electrolyte composition on micro-structure and phase constituents of the boride layers were discussed. Finally, some unsolved problems and the future trends of plasma electrolytic boriding technology are discussed and prospected.