铝及铝合金无铬钝化研究进展  

Research Progress in Chromium-free Passivaton of Aluminium and Aluminium Alloy

作　　者：崔珊[1] 安成强[1] 郝建军[1] 

机构地区：[1]沈阳理工大学环境与化学工程学院,沈阳110159

出　　处：《表面技术》2016年第6期63-69,共7页Surface Technology

摘　　要：铝合金可加工成各种板材、型材、铝铸件,为了减少其在工业环境中的腐蚀损失,需进行钝化处理。钝化常作为涂层的预处理步骤,钝化膜能增强铝合金表面与有机涂层的结合力,进一步提高涂层对基体的防护能力。目前无铬钝化主要是钼酸盐钝化、稀土盐钝化、锆/钛盐钝化及有机物钝化,因此对这几种主要化学钝化法的研究进程及现状进行了综述。钼酸盐复配其他盐协同缓蚀,能够获得更强的耐腐蚀性能。稀土盐中加入强氧化剂和成膜促进剂,可以简化处理工艺,降低腐蚀电流。锆、钛盐中加入有机物形成复合膜,能够改善单一膜层的耐腐蚀性能,提高与基体的结合力。硅烷在铝合金表面形成交联结构,从而表现出良好的封闭效果。在硅烷中加入纳米粒子可以获得更好的膜层表面形貌,加入稀土及其氧化物可提高耐腐蚀性能。硅烷两步法成膜过程中,成膜次序不同能够获得不同的膜层物理性能和耐蚀效果。最后,对未来无铬钝化工艺的研究方向进行了展望。Aluminum alloy can be processed into a variety of sheets, profiles and aluminum casting. Passivation of aluminum alloy is required in order to reduce its corrosion damage in the industrial environment. Passivation is often used as a coating pretreatment step and the passivate film can enhance the adhesion strength between the aluminum alloy surface and the organic coating, further improving the protection ability of coating. At present, chromium-free passivation mainly includes molybdate passivation, rare earth salt passivation, zirconium/titanium salt passivation and organic passivation. In this paper, the research process and current situation of these main chemical passivation methods were summarized. Compounding of molybdate with other salts results in enhanced inhibition of corrosion leading to stronger corrosion resistance. Addition of strong oxidizer and film-forming promoter into rare earth salts can simplify the process and reduce the corrosion current. Adding organic matter to Zirconium and titanium salts to form composite films can improve the corrosion resistance of the single film layer and can improve the binding force with the matrix. Silane forms a crosslinking structure on the aluminum alloy surface, and showed a good sealing effect. Adding nanoparticles into silane can obtain better film surface morphology, whereas adding rare earth and its oxides can improve the corrosion resistance. Altering the film forming order in the silane two-step film-forming process can get different membrane layer physical properties and corrosion resistance. Finally, the future research direction of chromium-free passivation technology was prospected.

关 键 词：铝及铝合金 无铬钝化 耐腐蚀性 硅烷 复合膜 

分 类 号：TG174.45[金属学及工艺—金属表面处理]