摘要
对AZ31D镁合金表面镧转化膜及其耐蚀性进行了研究。用扫描电镜(SEM)和能谱仪(EDS)对膜层的形貌和组分进行研究,采用动电位极化曲线测试对膜层的耐蚀性进行研究。结果表明:膜的微观形态呈针状,膜层厚度约为8μm,对镁合金的覆盖作用良好;转化膜主要由镧和氧两种元素组成;镧转化膜在阳极极化过程中发生明显的钝化,腐蚀电位正移约500mV,腐蚀电流密度降低2个数量级,明显提高了AZ 31D镁合金的耐蚀性能。
The lanthanum-based conversion coating on AZ 31D magnesium alloy and its corrosion resistance were investigated.The morphology and composition of the coating were studied by scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS） respectively.The corrosion resistance of the coating was assessed by means of potentiodynamic polarization measurements.The results show that the conversion coating,with a needle like micro-morphology,is about 8 μm thick,mainly composed of La and O,and has a good covering power to magnesium alloy;the coating is obviously passivated during anodization,the corrosion potential moves positively about 500 mV,and the corrosion current density decreases by two orders of magnitude,obviously improving the corrosion resistance of AZ 31D magnesium alloy.
出处
《电镀与环保》
CAS
CSCD
北大核心
2010年第3期33-35,共3页
Electroplating & Pollution Control
关键词
镁合金
镧
转化膜
耐蚀性
magnesium alloy
lanthanum
conversion coating
corrosion resistance
