(1. 湖南大学 材料科学与工程学院，长沙 410082；
2. 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 研究2A97铝锂合金在硅酸盐电解液中等离子电解氧化膜的生长规律，分析直流条件下电流密度、氧化时间等电参数对氧化陶瓷膜的表面和截面形貌、成分和相组成以及耐蚀性的影响。结果表明：等离子电解氧化处理提高了铝锂合金的耐腐蚀性能，但处理时间过长，膜层微观结构中缺陷增多，对膜层的耐蚀性带来不利影响，提高电流密度对膜层的耐蚀性也没有明显的影响。铝锂合金的等离子电解氧化膜微观结构中存在两类不同放电类型导致的特征结构，其中来源于基体/膜层界面的火花放电生成的结构含有较多的Al，而氧化膜表层或浅层的火花放电主要在膜层表面生成含有较多电解液成分的菜花状结构。膜层的相结构主要为γ-Al2O3。
关键字: 铝锂合金；等离子电解氧化；耐蚀性
（1. College of Materials Science and Engineering, Hunan University, Changsha 410082, China;
2. School of Materials Science and Engineering, Central south University, Changsha 410083, China）
Abstract:The plasma electrolytic oxidation(PEO) processes of 2A97 aluminium-lithium alloy in silicate electrolyte were studied. The PEO processes were carried out with DC regime, and the factors such as current density and treatment time on the morphologies of surface and the cross section of the coatings and the corrosion resistance of coatings were analyzed. The results show that the PEO processing enhances the corrosion resistance of the aluminium-lithium alloy, however, the corrosion resistance will be deteriorated by long processing time, due to more defects developed in the coatings, and the corrosion resistance of the coatings is also little affected by increasing the current density. There are two types of microstructures existing in the PEO coatings of aluminium-lithium alloy, which are resulted from the different types of discharging. The microstructure resulted from the discharge originated at substrate/coating interface contains more content of Al, while the discharge happening on the surface or shallow depth of PEO coating causes the formation of the cauliflower-like structure with electrolyte species on the surface of the PEO coatings. The main phase composion of the coatings is γ-Al2O3.
Key words: aluminium-lithium alloy; plasma electrolytic oxidation; corrosion resistance
