镀锌钢板硅烷与稀土铈盐、镧盐复合钝化的性能及机理  

Properties of Galvanized Steel Passivated by Silane and Rare Earth Cerium and Lanthanum

作　　者：彭天兰[1] 满瑞林[1] 梁永煌[1] 

机构地区：[1]中南大学化学化工学院,湖南长沙410083

出　　处：《材料保护》2009年第3期5-8,共4页Materials Protection

摘　　要：试验采用γ-氨丙基三乙氧基硅烷(γ-APS)协同稀土铈盐和镧盐钝化镀锌钢板。通过先在试样表面自组装一层γ-APS薄膜,再沉积稀土转化膜制备硅烷稀土复合膜。采用电化学交流阻抗技术(EIS)、盐雾试验检测复合膜的耐腐蚀性,结果表明复合膜的耐腐蚀性和致密性相对于单一硅烷、稀土转化膜大幅度提高,其中硅烷-铈盐复合膜比硅烷-镧盐复合膜耐腐蚀,中性盐雾试验时间达到76h。原子力显微镜检测结果表明,复合膜相对于单一稀土转化膜平整。EDS检测结果得出,硅烷与稀土化合物发生了协同作用,促进了稀土转化膜在锌表面沉积。初步探讨了复合膜的成膜机理和耐腐蚀机理。Amino-propyl-triethoxyl silane (γ-APS) was coopera-ted with rare earth salts of cerium and lanthanum to passivate gal-vanized steel. Thus self-assembled monolayer of-y-APS was first-ly prepared on the galvanized steel,followed by introducing of rare earth conversion coatings to generate silane -rare earth com-posite passivation coatings. The corrosion protection ability of the composite passivation coating was studied via electrochemical im-pedance spectroscopy and neutral salt spray test. The morphology of the composite coating was observed using an atomic force mi-croscope. And the film-formation mechanism and corrosion resist-ant mechanism of the composite passivation coating were ex-plored. Results indicate that the compactness and corrosion re-sistance of the composite coating was significantly improved as compared with self-assembled silane film or rare earth conversion coating. And silane -cerium salt composite coating had a salt -spray lifespan of 76h,showing better corrosion resistance than si-lane -lanthanum salt composite coating. Moreover,the composite coating was smoother than self-assembled silane film or rare earth conversion coating. Owing to the synergistic effect between silane and rare earth,the deposition of the rare earth conversion film on galvanized steel was promoted.

关 键 词：铈盐 镧盐 钝化 硅烷 稀土 交流阻抗 耐腐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]