陶瓷改性环氧涂层的腐蚀行为

摘要

将400目活性硅微粉与1 250目氧化铝粉(统称陶瓷粉末)按质量比1∶1共混后加入环氧树脂中制得陶瓷改性环氧涂料.利用电化学阻抗谱研究了陶瓷改性环氧涂层与纯环氧涂层在3.5％ NaCl溶液中的腐蚀行为和失效过程.通过静态挂片实验考察了涂层在各种介质中的平均腐蚀速率.结果表明,加入陶瓷粉末显著提高了环氧涂层的耐蚀性,增大了涂层的电阻,失效周期延长了15d,在5％ H2SO4溶液、5％ NaOH溶液和92号汽油中的平均腐蚀速率分别降低了约60％、60％和75％.%A ceramic-modified epoxy coating was prepared using epoxy resin and a mixture of active silicon powder with a mesh size of 400 and alumina powder with a mesh size of 1 250,which were collectively called as ceramic powder and blended at a ratio of 1∶1 by weight.The corrosion behavior and failure process of the ceramic-modified epoxy coating and pure epoxy coating were studied by electrochemical impedance spectroscopy in a 3.5％ NaCl solution.The average corrosion rates of the coatings in various media were analyzed by static coupon test.The results showed that adding ceramic powder greatly improves the corrosion resistance of epoxy coating,as shown by increased electrical resistance,prolonged failure period for 15 d,and about a 60％,60％ and 75％ decrease in average corrosion rate in 5％ H2SO4 solution,5％ NaOH solution and 92 RON gasoline respectively.