纯镁表面有机-无机杂化膜的防腐蚀性能

Anti-corrosion Performance of Organic-inorganic Duplex Coating on Magnesium Surface

以γ-氨丙基三甲氧基硅烷(γ-APS)为前驱体,采用溶胶-凝胶法制备硅烷溶液,并采用浸涂法在纯镁表面制备有机-无机杂化腐蚀保护膜。金相显微镜对有机-无机杂化膜的表面形貌观察表明,有机-无机杂化膜比铬钝化膜更均匀致密;对有机-无机杂化膜进行动电位极化曲线测定及试验后的显微形貌表明,与铬钝化膜相比,有机-无机杂化膜的自腐蚀电位更正,腐蚀电流密度更小,耐腐蚀性能更好。且有机-无机杂化膜无污染。该工艺可以有效取代铬钝化工艺。

Using γ-aminopropyltrimethoxysilane （γ-APS） as precursor, silane solution was prepared by sol-gel method, and then the organic-inorganic duplex protecting coating on Mg was prepared by Mg dipped into the silane solution. The surface morphology of the organic-inorganic hybrid coating was observed by metallographic microscopy. The results show that the organic-inorganic duplex protecting coating is smooth and more adhesive than the chromate film. Potentiodynamic polarization curve measurement and metallographic microscopy results show that the corrosion potential of the organic-inorganic duplex protecting coating is higher and corrosion current is smaller than those of the chromate film, and thus the coating possesses better anti-corrosion performance. The organic-inorganic duplex protecting coatings is environmentally friend. The suggested process can replace the chromate process effectively.