Sealing Treatment of Plasma-Sprayed Cr3C2-NiCr/Al2O3-TiO2 Coating by Aluminum Phosphate Sealant Containing Al2O3 Nanoparticles
- 11 October 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in Journal of Thermal Spray Technology
- Vol. 31 (1-2), 269-281
- https://doi.org/10.1007/s11666-021-01263-2
Abstract
A typical structure of thermal spray coatings consisted of molten particles, semi-molten particles, oxides, pores, and cracks. These factors caused the porosity of sprayed coatings, leading to a significant influence on the coating properties, especially their wear-corrosion resistance. In this study, a post-spray sealing treatment of Cr3C2-NiCr/Al2O3-TiO2 plasma-sprayed coatings was carried out, and then, their corrosion properties were evaluated, before and after the treatment. For the sealing process, aluminum phosphate (APP) containing Al2O3 nanoparticles (~10 nm) was used. The permeability of APP into the sprayed coating was analyzed by SEM-EDS. The treatment efficiency for porosity and corrosion resistance of sprayed coatings was evaluated by electrochemical measurements, such as the potentiodynamic polarization and electrochemical impedance spectroscopy. The wear-corrosion resistance of the coating was examined in 3.5 wt.% NaCl circulation solution containing 0.25% SiO2 particles. The sealing efficiency was evaluated by the percentage of the treated open pores in the coating. The obtained results showed that APP penetrated deeply through the coating and the incorporation of Al2O3 nanoparticles into APP sealant improved the sealing efficiency by 20% of open pores in comparison with the sealant without nano-Al2O3. The effect of the post-treatment on corrosion protection of the sprayed coating has been discussed.Keywords
This publication has 48 references indexed in Scilit:
- Effect of porosity sealing treatments on the corrosion resistance of high-velocity oxy-fuel (HVOF)-sprayed Fe-based amorphous metallic coatingsSurface and Coatings Technology, 2011
- Microstructure, spallation and corrosion of plasma sprayed Al2O3–13%TiO2 coatingsCorrosion Science, 2009
- Sliding wear and electrochemical corrosion behavior of plasma sprayed nanocomposite Al2O3–13%TiO2 coatingsMaterials Chemistry and Physics, 2009
- Effects of TiO2 on the mechanical properties of the Al2O3–TiO2 plasma sprayed coatingJournal of the European Ceramic Society, 2007
- Effects of the powder manufacturing method on microstructure and wear performance of plasma sprayed alumina–titania coatingsSurface and Coatings Technology, 2007
- Microstructure and properties of Al2O3-13%TiO2 coatings sprayed using nanostructured powdersRare Metals, 2007
- Low macroscopic field electron emission from surface of plasma sprayed and laser engraved TiO2, Al2O3+13TiO2 and Al2O3+40TiO2 coatingsSurface and Coatings Technology, 2004
- The corrosion behavior of plasma-sprayed Ni/Al–Al2O3 and Ni/Al–Al2O3+13 wt.% TiO2 graded ceramic coatings in 5%HCl solutionSurface and Coatings Technology, 2003
- Mechanisms of ceramic coating deposition in solution-precursor plasma sprayJournal of Materials Research, 2002
- Erosion of ceramic materials by a sand/water slurry jetWear, 1999