(1. 南昌大學 材料科學與工程學院，南昌 330031；
2. 南昌大學 機電工程學院，南昌 330031)
摘 要: 利用掃描電鏡、X射線衍射和質量損失等手段，研究預處理前后的表面形貌及質量變化和錫酸鹽化學轉化膜層表面形貌及其相組成，采用鹽霧和濕熱實驗箱檢驗膜層的抗腐蝕性能。結果表明：預處理前后鎂合金表面相組成基本不變，質量減少主要發(fā)生在酸洗階段，但變化不大；由于發(fā)生化學腐蝕和電化學腐蝕，預處理后表面在相界處出現(xiàn)較深的狹縫。化學轉化膜層主要由Mg、Al12Mg17和MgSnO3∙3H2O組成，表面由細小近球形顆粒密積而成，顆粒之間存在縫隙。經鹽霧和濕熱檢測，化學轉化膜層可以大大提高鎂合金基體的抗腐蝕性。
關鍵字: 鎂合金；錫酸鹽；化學轉化膜；抗腐蝕性
corrosion resistance of magnesium alloy
（1. School of Materials Science and Engineering, Nanchang University,
Nanchang 330031, China;
2. School of Mechanical and Electronic Engineering, Nanchang University, Nanchang 330031, China）
Abstract: The changes of morphology and mass in the process of pretreatment, the morphology and the phase constitution of chemical conversion film formed by stannate were studied using scanning electron microscope, X-ray diffraction and the mass loss method. The corrosion resistance of film were studied by salt spay test and damp test. The results show that the phase constitution before and after pretreatment is almost changeless and the mass diminishes a litter during acidic solution, and because of chemistry and electrochemistry corrosion, the deep micro flaw appears near between α and β phases. The conversion film is mainly composed of Mg, Al12Mg17 and MgSnO3∙3H2O, and the fine sphericity grain forms on the surface. The film can provide a good protection for the magnesium alloy.
Key words: magnesium alloy; stannate; chemical conversion film; corrosion resistance
