镁合金在大气环境中电偶腐蚀行为及规律的研究

Research on Atmospheric Galvanic Corrosion Laws of Magnesium Alloys

研究了北京大气环境下,AM50镁合金作为阳极发生不同程度的电偶腐蚀行为规律。结果表明其中镁合金与LY12铝合金偶接的电偶腐蚀效应最小。通过与其他地区室外暴晒的镁合金电偶腐蚀效应对比,表明环境因素,尤其是试验开始初期阶段的大气环境状况对于镁合金初期电偶腐蚀行为有着重要的影响。同时阴极材料、试验时间、试样尺寸(偶接面积)和试验环境都会对镁合金电偶腐蚀效应产生影响。采用XRD分析表面的腐蚀产物,用金相显微镜和扫描电镜(SEM)观察试样腐蚀后的表面形貌特征和腐蚀产物的结构,并用与之相连的能谱仪分析腐蚀产物中的元素组成。

In this paper the galvanic corrosion behavior laws of AM50 magnesium alloy coupled with different alloys in Beijing atmospheric environment were investigated. The results show that the magnesium alloys act as anode. The atmospheric galvanic effect of magnesium alloys coupled with LY12 aluminium alloy is the least in all of testing cathode alloys. The atmospheric galvanic effects in Beijing compared with other cities indicate that atmospheric environment is the most important factor. The atmospheric galvanic effects for magnesium alloys are affected by cathode alloy, testing time, sample size and environment condition. SEM, XRD and optical microscope were used to investigate the morphology changes on the surface of AM50 magnesium alloy.