ES150型纳米改性有机硅涂料的防护作用及其应用

Protective Performance of a Novel Silicone Coating ES150 Modified with Nano-particulate of Metal for AZ91D Mg-alloy

采用物理混合的方法制备了ES150型纳米改性有机硅涂料,并采用电化学阻抗技术、盐雾腐蚀实验和浸泡实验研究了涂层的防腐蚀性能。结果表明,清漆涂层存在大量的微孔,严重影响涂层的防护性能。纳米改性复合涂层的致密度显著提高,经6000 h盐水浸泡和5000 h中性盐雾腐蚀实验,涂层未出现起泡、剥落等破坏,涂层下的基体镁合金未发生腐蚀。在浸泡过程中涂层的阻抗保持在109Ω·cm2以上,具有优异的耐腐蚀性能。SO2加速腐蚀实验表明,ES150型纳米复合有机硅涂料实现了对飞机零部件在恶劣环境中的有效防护,实际应用效果显著。

A novel protective coating, namely ES150 silicone modified with nano-particulate of metal was prepared by physical blending process, which was further applied on AZ91 D Mg-alloy, and then the corrosion resistance of the coated alloy was evaluated by electrochemical impedance spectroscopy（EIS）, immersion test in 3.5%（mass fraction） Na Cl solution and neutral salt spray exposure. The results indicated that lots of micropores could be observed within the silicone lacquer coating, which deteriorates its protective efficiency. In contrast, the number of micropores decreased greatly for the modified silicone coatings with nano-particulate of metal. The modified ES150 coatings can withstand 6000 h immersion in3.5%Na Cl solution and 5000 h neutral salt spray exposure without blistering, peeling off or corrosion. Theimpedance of the coatings is larger than 109Ω·cm2 during immersion in 3.5%Na Cl solution. The SO2 accelerated corrosion experiments revealed that the coatings provide sufficient protectiveness for airplane workpieces.