ABSTRACT

Sealing treatment is an effective, environmentally friendly, and economical coating surface modification technology. To clarify the inorganic silicate sealing mechanism and concentration dependence on corrosion behaviour, HVAF-sprayed Fe-based amorphous metallic coatings (AMCs) were sealed by Na₂SiO₃ solution with various concentrations, and their microstructure, electrochemical performance, and surface chemistry were characterised in detail. The results showed that Na₂SiO₃, in the form of a silicon-oxygen bond (Si-O), could effectively bond with the coating surface inside the pore defects. In addition, the optimal concentration was proved to be 1 mol/L, and the corresponding passivation current density could be reduced to (2.38 ± 0.33) × 10⁻⁶A/cm², which was an order of magnitude lower than that of as-sprayed coating. This was due to the incomplete filling of the sealant at lower concentrations and the release of water vapour at higher concentrations. This work aims to provide guidance for the practical application of silicate sealing treatment.

摘要

封闭处理是一种有效、环保、经济的涂层表面改性技术。_{为了阐明无机硅酸盐封闭机理和浓度对腐蚀行为的依赖性，采用不同浓度的Na 2} SiO ₃溶液封闭HVAF喷涂铁基非晶金属涂层（AMC），并对其微观结构、电化学性能和表面化学进行了表征详细。结果表明Na ₂ SiO ₃以硅氧键（Si-O）的形式，可以有效地与涂层表面的孔隙缺陷内部结合。此外，证明最佳浓度为1 mol/L，相应的钝化电流密度可降低至（2.38±0.33）×10 -6 ^A /cm ²，比现有的钝化电流密度低一个数量级。 - 喷涂涂层。这是由于在较低浓度下密封胶填充不完全，而在较高浓度下则释放出水蒸气。本工作旨在为硅酸盐封堵处理的实际应用提供指导。