pH值对AZ91D镁合金表面植酸转化膜的影响  

Influence of pH Value on Phytic Acid Conversion Coating on AZ91D Magnesium Alloy

作　　者：陈言坤[1] 杜仕国[1] 鲁彦玲[1] 汪明球[1] 

机构地区：[1]军械工程学院三系,石家庄050003

出　　处：《表面技术》2010年第5期80-83,共4页Surface Technology

基　　金：军械工程学院基金资助项目(yjjsm09028)

摘　　要：在pH值不同的几种植酸转化液中对AZ91D镁合金进行表面转化处理,利用扫描电镜及自带能谱仪、Tafel曲线和阻抗谱等分析手段,结合NaCl水溶液点滴实验,研究了pH值对植酸转化膜表面成分及耐蚀性的影响。结果表明:在酸性条件下形成的植酸转化膜的耐蚀性较好;转化液的pH值会影响植酸螯合物的形成和转化膜的物质组成,进而影响转化膜的耐蚀性能;在酸性条件下,镁合金表面形成的植酸转化膜应属于电子导体膜,它阻碍了腐蚀介质与基体的接触,同时抑制腐蚀产物的扩散,对镁合金起到防护作用。The matrix metal,AZ91D magnesium alloy,was treated in solutions of phytic acid with different pH value.SEM,EDS,Tafel,EIS were adopted and spot test was carried out to investigate the influence of pH value on the composition and the corrosion resistance of conversion coating.Results show that the coating formed in acid solution can improve the corrosion resistance of magnesium alloy evidently.The pH value of solution has influence on formation,composition and corrosion resistance of the conversion coating.The conversion coating obtioned in acid solution is a kind of coating that hinders the contact between corrosion medium and matrix metal and inhibits the diffusion of corrosion products.

关 键 词：镁合金 植酸 转化膜 耐蚀性 

分 类 号：TG174.45[金属学及工艺—金属表面处理]