放电发射光谱在金属微弧氧化表面处理中的应用研究进展

Research progress in the application of optical emission spectroscopy in metalmicroarc oxidation surface treatment

液相火花放电现象是金属微弧氧化表面处理时典型特征,发射光谱(OES)技术是表征微弧放电光谱特征和探索微弧氧化机理的有效手段。本文综述了铝、镁、钛等金属微弧氧化过程中发射光谱的研究现状。介绍微弧放电区等离子体的电子温度、电子密度等特征参数计算原理。重点关注了不同金属基体材料、电参数及电解液组成条件下,等离子体放电行为对微弧氧化膜结构的影响规律,并比较不同放电模型的异同。基于OES谱线评估得到的各种金属微弧等离子体温度为3000~10000 K,为放电通道内快速熔化-凝固过程促进陶瓷膜生长机制提供证据。

Spark discharge phenomenon in solution is a typical characteristic in metal microarc oxidation(MAO)surface treatment,and the optical emission spectroscopy(OES)is an effective way of characterizing micro-discharge optical emission spectra and studying the MAO mechanism.In this paper,the research status of OES analyses in MAO process of Al,Mg,Ti and their alloys was reviewed,the calculation principle of electron temperature and density in microarc plasma discharge channels was introduced,and the influence of the plasma discharge behavior on the microstructure of MAO coatings at different metals,electrical parameters and electrolyte solutions was evaluated.Furthermore,the different discharge models on the basis of OES analyses were also discussed.The plasma temperature in microarc discharge zone for different metals calculated from OES was in the range of 3000-10000 K,which provided the evidence for the growth mechanism of ceramic coatings enhanced by quick molten-solidification process in discharge channel.