硅烷增强镁合金防腐有机涂层的研究

Study on the Anticorrosive Organic Coating for Magnesium Alloy by Silane Pretreatment

为了提高镁合金的耐腐蚀性能,结合硅烷处理和胶粘涂层技术在AZ31镁合金表面制备了环氧防腐涂层。通过扫描电镜对涂层表面形貌进行观察,采用划格法、浸泡法及盐雾试验等分析镁合金表面硅烷处理对有机涂层的附着力及耐蚀性的影响。研究结果表明:采用KH-550型硅烷进行处理后,镁合金基体与有机涂层之间形成化学键,涂层与基体结合牢固,附着力为1级,耐饱和盐水23d不起泡。硅烷处理明显提高了有机涂层对基体的附着力和耐蚀性,因此,硅烷+胶粘涂层的方法可用于镁合金的表面防腐。

The epoxy anticorrosive coating by combination silane pretreatment and adhesive coating methods was prepared on AZ31 magnesium alloy to improve its corrosion resistance. The morphology of coating was observed by SEM. The effects of silane pretreatment on the adhesion and corrosion resistance of the coating were analyzed by using scribe, immersion, salt spray tests and so on. The results show that after the pretreatment of AZ31 magnesium alloy with KH-550 silane coupling agent, there is chemical bond between the coating and the substrate, the adhesion of the coating can reach grade 1, and there is no change in saturated NaCl solution for 23d. Silane pretreatment can enhance remarkably the adhesion and corrosion resistance of the coating, so silane pretreatrnent and adhesive coatings are suit to magnesium alloys for protection.