摘要
以"稀土盐"代替传统"铬酸盐"进行航空镁合金表面化学转化处理,用金相显微镜对稀土转化膜表面形貌进行观察,通过极化曲线和浸泡挂片试验对基体试样和膜层试样进行模拟腐蚀试验。实验表明,室温条件下,在3g/L CeCl3·H2O、5g/L KMnO4等物质组成的稀土盐转化液中进行化学转化处理,镁合金试样表面生成一层黄褐色转化膜,且该膜层具有很好的耐蚀性能。用化学热力学原理对稀土盐化学转化膜组成及膜形成过程进行分析,研究表明,稀土盐化学转化膜层的成分有MgO、CeO2、MnO2、Mg(OH)2和Ce(OH)4等物质。在稀土盐化学转化初期,试样增重率随时间快速增长,化学转化进行到30min时,试样增重率几乎不变。
Instead of the chromate salt chemical conversion treatment for aerospace magnesium alloys, a technology of the rare earth salt chemical conversion is studied and the corrosion resistance is evaluated as well. These micrographs of specimen surface are investigated by metallographic microscope. The corrosion behaviors of magnesium alloy and conversion coating are assessed by means of potentio- dynamic polariza- tion curves and immersion tests. The experimental results indicate that a yellow-brown conversion coating is formed subsequently on the specimen surface, the conversion technology condition is a mixture solution including 3 g/L CeCl3 ~ H20,5g/L KMnO4 and the other at room temperature. The formation of the rare earth conversion coating and the composition of the coating are discussed by the principle of thermodynam- ics. The research results indicate that the composition of the coating includes MgO, CeO2, MnO2, Mg （OH）2 and Ce （OH）4. During the initial of the rare earth salt conversion, mass gain is a linear growth with time. After 30min, mass gain is approximately unchanged.
出处
《空军工程大学学报（自然科学版）》
CSCD
北大核心
2014年第2期16-19,共4页
Journal of Air Force Engineering University(Natural Science Edition)
基金
国家自然科学基金资助项目(11204378)
关键词
航空镁合金
稀土
化学转化
耐蚀性能
aerospace magnesium alloy
rare earth
conversion coating
corrosion resistance
