7B04-T6铝合金新型纳米涂层外场腐蚀环境下电化学性能研究

目的评估自然暴露环境下新型纳米涂层的耐蚀性能。方法选取西沙永兴岛海洋环境作为自然暴晒场,对试验件做预损伤处理后,开展7B04-T6铝合金/新型纳米涂层与天津灯塔涂料股份有限公司典型防腐涂层在高盐雾、高湿热、强太阳辐射等综合腐蚀环境下的外场暴露试验,利用电化学阻抗技术对暴晒前后的两类涂层试样在3.5%NaCl溶液中浸泡不同时间的耐蚀性能进行对比研究。结果两类涂层外场暴露试验后,电化学阻抗值下降,且随着在3.5%NaCl溶液中浸泡时间的增加,Rp值不断减小,CPE-T值不断增大。结论新型纳米涂层在外场暴露试验1年后,并未发生腐蚀损伤失效,仍具有较好的耐盐水性,但其耐候性差于天津灯塔涂料股份有限公司试验涂层。

Electrochemical Property for 7B04-T6 Aluminum Alloy Surface Protective Coating in the Presence of Outfield Corrosion

Objective To evaluate the corrosion resistance of new nano coating under the conditions of natural exposure. Methods Yongxing Island in Paracel was selected as a natural exposure field. The test pieces were treated for pre-damage. 7b04-T6 aluminum alloy/new nano coating and typical corrosion resistant coating of Tianjin Lighthouse Coating Co., Ltd. were tested for outfield exposure under conditions of high salt fog, typical hot and humid, strong ultraviolet radiation and other com-prehensive corrosion environment. The electrochemical impedance technology was used to compare and research two kinds of coatings immersed in 3.5% NaCl solution for different period before and after the exposure. Results After field exposure test of two coatings, the electrochemical impedance value decreased. With the increase of 3.5% NaCl solution soaking time, the Rp value was decreased constantly, and CPE-T value increased constantly. Conclusion The new nano-coating has no corrosion loss and failure after field exposure test for 1 year, and still has good salt-water resistance, but its weather resistance is worse than that of the coating of Tianjin Lighthouse Coating Co., Ltd.