通过对7A04-T6包铝合金及去包铝合金与三种橡胶抗老化涂层材料在高温、高湿环境中的接触腐蚀产物SEM形貌分析及EDS成分分析,表明铝合金与橡胶抗老化涂层接触腐蚀形貌特征为点蚀,腐蚀严重时试样表面局部或全部被大量腐蚀产物所覆盖,腐蚀产物的主要元素为Al,C,O,Mg,Zn,Cl,Si,S。提出了铝合金与橡胶抗老化涂层“接触-扩散-吸附/沉积物层与电解质薄液膜层形成/腐蚀闭塞区形成/阴离子加速自催化腐蚀/点蚀-晶间腐蚀-剥落腐蚀”的接触腐蚀过程及机理。

The contact corrosion mechanism between 7A04-T6 aluminum alloy and three antiaging coatings of the rubber fuel tank was studied.The corrosion morphology,constituents and their content in corrosion product of clad 7A04-T6 alloy and 7A04-T6 alloy were analyzed by SEM and EDS after contact corrosion happened in high temperature and high humidity environment.Results demonstrated that corrosion morphology were piting,localized corrosion or corrosion product layer.The main elements in corrosion product of clad 7A04-T6 alloy and 7A04-T6 alloy were Al,C,O,Mg,Zn,Cl,Si,S.The process and mechanism of contact corrosion between aluminum alloy and antiaging coatings were conceived as: contact-diffusion-adsorption/formation of facilitates and thin electrolyte layer/occlusive corrosion region/anion accelerates the self-catalysis corrosion/pitting-intergranular corrosion-exfoliation corrosion.