(1. 湖南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410082；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究2A97鋁鋰合金在硅酸鹽電解液中等離子電解氧化膜的生長規(guī)律，分析直流條件下電流密度、氧化時間等電參數(shù)對氧化陶瓷膜的表面和截面形貌、成分和相組成以及耐蝕性的影響。結(jié)果表明：等離子電解氧化處理提高了鋁鋰合金的耐腐蝕性能，但處理時間過長，膜層微觀結(jié)構(gòu)中缺陷增多，對膜層的耐蝕性帶來不利影響，提高電流密度對膜層的耐蝕性也沒有明顯的影響。鋁鋰合金的等離子電解氧化膜微觀結(jié)構(gòu)中存在兩類不同放電類型導(dǎo)致的特征結(jié)構(gòu)，其中來源于基體/膜層界面的火花放電生成的結(jié)構(gòu)含有較多的Al，而氧化膜表層或淺層的火花放電主要在膜層表面生成含有較多電解液成分的菜花狀結(jié)構(gòu)。膜層的相結(jié)構(gòu)主要為γ-Al2O3。
關(guān)鍵字: 鋁鋰合金；等離子電解氧化；耐蝕性
（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
