Protection Performance of Plasma Sprayed Al₂O₃-13 wt%TiO₂ Coating Sealed with an Organic-inorganic Hybrid Agent

Abstract

An organic-inorganic hybrid sealing agent was fabricated and used in the plasma sprayed Al₂O₃-13 wt%TiO₂ coating, and conventional silicone agent was also used for comparison. Protection performance of the coatings was comprehensively evaluated based on both anti-corrosion and anti-biofouling properties. The results reveal that the sealing treatment is remarkably useful to decrease the porosity of the coating, and the porosity of the coating sealed with the hybrid agent is only 0.035%. Immersion corrosion test and Tafel polarization test reveal that the sealed coating with the hybrid agent exhibits a better corrosion resistance by compared with the coating sealed with silicone agent. The corrosion current density i _corr of the hybrid agent sealed coating is only 0.7 × 10⁻⁶ A·cm⁻². Moreover, anti-biofouling tests both in the outdoor analogue hydraulic environment and in the natural marine environment prove that the mentioned novel coating presents a better combination of corrosion resistance and anti-biofouling property by compared with the other coatings, and it could be used as a protection of metal components in the marine environment.

Keywords

plasma sprayed coating / marine corrosion / Al₂O₃-13 wt%TiO₂ / corrosion resistance / sealing treatment