Cl^-对镁-铝合金β相模型合金表面膜稳定性的影响  

Influence of Cl^- on the stability of surface films on the β phase model alloy of magnesium-aluminum alloys

作　　者：贾瑞灵[1] 吴承斌[2] 严川伟[2] 王福会[2] 

机构地区：[1]内蒙古工业大学内蒙古轻金属材料重点实验室,呼和浩特010051 [2]中国科学院金属研究所金属腐蚀与防护国家重点实验室,沈阳110016

出　　处：《北京科技大学学报》2010年第4期466-471,共6页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(No.50571105)

摘　　要：采用电化学阻抗测试技术(EIS)、Mott-Schottky方法对β相模型合金在Cl-溶液环境中形成的表面膜的稳定性和半导体特性进行研究.结果表明,Cl-浓度的增加,使β相表面膜形成和活化溶解的趋势均加剧,即表面膜的稳定性变差.原因在于Cl-浓度较低时,β相表面膜的半导体类型为P型,P型半导体膜是一种阳离子导体膜,Cl-很难通过迁移扩散的方式穿过表面膜.随着Cl-浓度的增大,β相表面膜的半导体类型转变为N型,N型半导体膜便于Cl-穿越膜层到达膜层底部,继续腐蚀金属并使表面膜发生破裂.The stability and semiconductive property of surface films formed on the β phase model alloy were investigated by means of electrochemical impendence spectroscopy（EIS）and Mott-Schottky approach in solutions containing Cl^-.The results indicate that the increase of Cl^-concentration may accelerate the formation and active dissolution of the films on the surface of β phase,leading to the deterioration of film stability.This phenomenon can be attributed to the fact that the semiconductive type of the films of β phase is P-type in case of solutions with low Cl^-concentration.As P-type semiconducting films are cationic conductor films,it is difficult for Cl^-to penetrate in a way of transportation and diffusion.When the Cl^-concentration increases,the semiconductive type of the films may turn into N-type where Cl-migrates or diffuses in the films,penetrates through the bottom of the films,causes continuous corrosion of the substrate and finally the surface films break down.

关 键 词：镁-铝合金 氯离子 腐蚀 表面膜 

分 类 号：TG146.2[一般工业技术—材料科学与工程]