铝表面硅烷及缓蚀剂协同改性研究

Synergistic Surface Modification of Aluminum by Silane and Corrosion Inhibitor

试验采用硅烷双-[3-(三乙氧基)硅丙基]四硫化物(BTESPT)和长链烷基有机酸酯缓蚀剂A钝化金属铝,通过先后将试样浸入BTESPT溶液,A分子溶液中,取出在100℃固化12h制备耐腐蚀的钝化膜。析氢试验、碱浸失重试验、盐雾试验和电化学测试均证明钝化后的试样耐腐蚀性能明显高于空白样。膜中不含重金属和氟化物,通过了欧盟ROHS指令。利用SEM观察了复合膜的表面微观形貌,结合电化学试验初步探讨了复合膜的耐蚀机理。并探讨了复合膜的成膜机理。

Bis-[-3-(triethoxysilyl)propyl] tetrasulfide(a kind of silane,abbreviated as BTESPT)and an organic acid ester with long chain alkyl group(inhibitor A throughout)were used to synergistically passivate aluminum.Thus the Al samples were sequentially immersed in the silane(BTESPT)solution and inhibitor A solution,allowing the formation of compact hydropho-bic complex film on the surface of the Al surfaces.The final syn-ergistic passivation film was obtained by drying the hydrophobic complex film at 100℃ for 12 h.The corrosion resistance of the synergistic passivation film was evaluated using hydrogen-evolution test,weight loss test in alkaline solution,salt-fog test,and electrochemical test.The microstructure of the passivation film was examined by means of scanning electron microscopy(SEM),and the film-formation mechanism and the corrosion resistant mechanism of the film were discussed.It was found that the complex passivation film had excellent corrosion resistance.No heavy metals and fluorides were detected in the composite passivation film,meeting the requirements of European ROHS standard.