摘要
为了有利于环保,采用磷化工艺对AZ31B镁合金进行化学镀镍前处理。采用直观法、扫描电子显微镜和阴极极化曲线法对磷化膜及其化学镀镍层进行了分析。结果表明:AZ31B镁合金表面经磷化处理后得到了良好的化学镀镍层;AZ31B镁合金化学镀镍层的耐蚀性随磷化时间的延长先增加后减小,当磷化时间为75 s时,化学镀镍层的腐蚀电势比直接化学镀镍层正移650 mV,腐蚀电流下降3个数量级。
AZ31B Mg alloy was pretreated with a phosphating fluid,followed by electroless Ni plating.Resultant phosphating coating and eleotroless Ni coating were evaluated by means of visual method,observation with a scanning electron microscope and measurement of cathodic polarization curves.Results show that desired electroless Ni coating can be obtained on AZ31B magnesium alloy when the substrate is pretreated in phesphating fluid.The corrosion resistance of electroless Ni coating initially rose but declined later with extending time of phos-phating.In the meantime,as compared with directly electroless Ni coating,the one prepared on Mg alloy substrate pretreated in the phosphating fluid for 75 s possessed much better corrosion resistance,having a corrosion potential shifted towards positive side by 650 mV and a corrosion current reduced by three orders of magnitude.
出处
《材料保护》
CAS
CSCD
北大核心
2011年第6期37-39,7-8,共3页
Materials Protection
关键词
磷化
化学镀镍
AZ31B镁合金
耐蚀性
phosphating
electroless Ni coating
AZ31 B Mg alloy
corrosion resistance
