摘要
利用化学转化处理在AZ31镁合金表面制备两种非铈稀土防护膜——镧膜和钐膜。采用电化学阻抗谱(EIS)方法评定膜层的防护效果,采用扫描电子显微镜(SEM)和能量色散谱(EDS)表征膜层的表面形貌及组成。结果表明:镁合金表面镧、钐转化膜均由相应的稀土氢氧化物/氧化物及基体金属氢氧化物/氧化物组成;镧转化膜均匀、致密,对基体金属防护效果好,而钐转化膜呈碎片状,部分覆盖基体表面,防护作用很弱。初步探讨了成膜机制。
The lanthanum and samarium protective coatings were prepared on AZ31 magnesium alloy by chemical conversion treatments. The protection ability, surface morphology and composition of the coatings were characterized by using electrochemical impedance spectroscopy （ EIS ） , scanning electron microscopy （SEM） and energy dispersive spectroscopy （ EDS ）, respectively. The results showed that the lanthanum and samarium conversion coatings consisted of hydroxides/oxides of corresponding rare earth elements and the substrate alloy. The lanthanum conversion coating was homogenous and compact, which provided strong protection for the substrate. The samarium conversion coating covered the substrate partly as fragments, which had limited protection. The formation mechanism of the coatings was discussed briefly.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2009年第3期375-378,共4页
Journal of the Chinese Society of Rare Earths
基金
国家杰出青年科学基金(50725413)
重庆市自然科学基金(CSTC2008BB4174)
中国博士后科学基金(20080430743)资助项目
关键词
镁合金
稀土转化膜
镧
钐
防护
magnesium alloy
rare earth conversion coating
lanthanum
samarium
protection
