Microstructure and corrosion behavior of HVAF-sprayed Fe-based composite coatings doped TiB2 and CNTs

作者：Liu, Xiaoqing; Zeng, Dechang^*; Wu, Yaosha; Zheng, Zhigang; Qiu, Zhaoguo^*

来源：Corrosion Science, 2022, 208: 110629.

DOI：10.1016/j.corsci.2022.110629

• HVAF spraying
• Fe-based coating
• Carbon nanotube
• Corrosion resistance

Fe-based composite coating doped well-dispersed titanium boride (TiB2) and carbon nanotubes (CNTs) were successfully fabricated via high velocity air fuel (HVAF) spraying. The microstructure and corrosion behavior of Fe-based metallic, Fe-TiB2 cermet and Fe/(TiB2-CNTs) coatings were comparatively investigated. It is found that doping TiB2, especially further doping 2.5 vol% CNTs could remarkably render the coatings lower porosity, favorable microstructure, superior hydrophobicity and then enhanced corrosion resistance. Thanks to the densest microstructure and the formation of passive films, pitting instead of severe etch groove in TiB2-Fe interface inside splats and inter-splats was the main corrosion mechanism of the Fe/(TiB2-CNTs) coating.