摘要
采用两步法制备甲基硅酸盐/硅酸盐复合膜,通过扫描电子显微镜(SEM)及EDS分析、红外光谱(FT-IR)分析、接触角测试、中性盐雾实验和极化曲线等对膜层的微观形貌、化学组成、疏水性及耐腐蚀性能进行了研究,并与单独的硅酸盐膜、甲基硅酸盐膜进行对比。利用电化学阻抗谱和等效电路拟合分析甲基硅酸盐/硅酸盐复合膜的防腐蚀机理。结果表明:甲基硅酸盐/硅酸盐复合膜层的外层与单独甲基硅酸钠膜的成分含量基本一致,但其微观形貌与单独甲基硅酸盐膜表面布满裂纹不同,复合膜层的表面均匀平整、没有开裂,膜层附着性好。单独硅酸盐膜为亲水性膜层,甲基硅酸盐/硅酸盐复合膜表现出疏水性,与单独硅酸盐膜相比,复合膜对腐蚀的阴极过程的抑制明显增强,极化阻抗增加至单独硅酸盐膜的5倍以上,复合膜的总阻抗值超过100 kΩ·cm~2,复合膜的腐蚀电流密度比单独硅酸盐膜的降低了60%。
Methyl silicate/silicate composite coatings were prepared using a two-step method.The morphology,chemical composition,hydrophobicity and corrosion resistance of the coatings were investigated by scanning electron microscope(SEM)with energy dispersive spectrometer(EDS),Fourier transform infrared spectroscopy(FT-IR),contact angle tests,neutral salt spray(NSS)tests and potentiodynamic polarization curve,respectively,and were compared with those of single silicate coating and methyl silicate coating.The corrosion mechanism of methyl silicate/silicate composite coatings were analysed by electrochemical impedance spectroscopy(EIS)as well as equivalent circuit.The results show that the compositions of methyl silicate/silicate composite coatings outer layer are the almost same as the compositions of single methyl silicate coating,different from single methyl silicate coating with lots of cracks on surface,the composite coatings are uniform and smooth with no crack,and the adhesion is good.Single silicate coating is hydrophilic.Compared with single silicate coating,methyl silicate/silicate composite coating is hydrophobic,corrosion inhibition of cathodic process is obviously enhanced,and polarization impedance of the composite coating is 5 times more than that of the single silicate coating,total impedance values of composite coatings are more than 100 kΩ·cm2,corrosion current density of composite coatings is reduced by 60%.
作者
张双红
杨波
翟伟
李爽
孔纲
ZHANG Shuang-hong;YANG Bo;ZHAI Wei;LI Shuang;KONG Gang(Guangzhou Special Pressure Equipment Inspection and Research Institute,Guangzhou 510663,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2021年第5期163-170,共8页
Journal of Materials Engineering
基金
广州市科技计划项目(201804010273)
广州市科技计划项目(202002030368)
广东省质量技术监督局科技项目(2017PT05)
广东省市场监督管理局科技项目(2018CT37)。
关键词
甲基硅酸钠
疏水性
硅酸盐复合膜
耐腐蚀性
sodium methyl silicate
hydrophobicity
silicate composite coating
corrosion resistance
