(1. 沈陽工業(yè)大學(xué) 理學(xué)院，沈陽110870；
2. 中國科學(xué)院金屬研究所 材料環(huán)境腐蝕中心，沈陽110016)
摘 要: 采用新型氟鈦酸鹽電解液對AM60 鎂合金進行微弧氧化處理，通過改變電流密度、氧化時間、頻率和占空比4 種電參數(shù)進行對比研究，采用SEM(掃描電子顯微鏡)觀察材料的表面及截面形貌，采用EDX (能量色散X射線光譜儀)以及XRD(X 射線衍射儀)確定其化學(xué)成分和相組成，通過極化曲線和阻抗譜對材料的耐蝕性進行評價。最終確定其最佳電參數(shù)如下：電流密度3 A/dm2、氧化至420 V、頻率800 Hz、正占空比30%。所形成氧化膜表面的微孔在成膜過程被原位封閉，有效地解決了微弧氧化膜疏松多孔的問題。在最佳工藝條件下獲得的微弧氧化膜自腐蝕電流密度可以達到1×10-7 A/cm2，其耐蝕性能優(yōu)于傳統(tǒng)電解液制備的微弧氧化膜的耐蝕性能。
關(guān)鍵字: 鎂合金；氟鈦酸鹽；微弧氧化；電參數(shù)；原位封孔
（1.College of Science,Shenyang University of Technology,Shenyang 110870,China;
2. Environmental Corrosion Center,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China）
Abstract:A new fluotitanate electrolyte was used for preparing microarc oxidation (MAO) film on AM60 Mg alloys. Four electrical parameters,including current density,oxidation time,frequency and duty cycle,were investigated for determining the optimum parameters. The surface and cross-section morphologies were characterized by SEM (Scanning electron microscopy). The chemical composition and phase structure were analyzed by EDX (Energy dispersive X-ray spectroscopy) and XRD (X-ray diffractometry). The corrosion resistance was evaluated by polarization and EIS (Electrochemical impedance spectroscopy) measurements. The optimal electrical parameters are determined as follows: current density 3 A/dm2,oxidation at constant current to 420 V,frequency 800 Hz and positive duty cycle 30%. The micro-pores on the surface of the film are in-situ sealed during the film formation process,thus avoiding the porous structure as the traditional MAO film. The corrosion current density of the MAO film under the optimum processing conditions can reach 1×10-7 A/cm2,which is superior to the corrosion resistance of traditional MAO films.
Key words: Mg alloy; fluotitanate; microarc oxidation; electrical parameter; in-situ sealing pore
