Enhanced wear and corrosion resistance of CeO2/WSAR-sealed TiN coatings for extreme environments

Metallic materials are widely utilized across various engineering applications. To ensure prolonged service life under complex operational conditions, surface coatings are frequently employed, with plasma-sprayed TiN coatings being a representative example. However, inherent process-induced pores inevitably form during coating deposition, compromising service longevity. Sealing treatments represent a commonly adopted post-processing strategy to mitigate this issue. This study developed a corrosion and wear resistant composite sealant by incorporating the rare earth oxide CeO 2 into waterborne silicone acrylic resin (WSAR). This approach synergistically combines the high sealing capability of the organic resin with the corrosion resistance and nanoscale properties of inorganic CeO 2 . The optimal component ratio was systematically investigated. Results demonstrate that the sealant exhibits optimal protective performance at a CeO 2 doping of 0.4 wt%. At this concentration, nanoparticles are well-dispersed, and the sealant exhibits excellent fluidity, enabling dense filling of both surface and internal pores. Compared to coatings sealed solely with WSAR, a significant improvement in coating density is observed. The optimally sealed coatings exhibit substantially enhanced corrosion resistance and wear resistance. However, further increasing the CeO 2 content leads to nanoparticle agglomeration and inhomogeneous mixing within the sealer system. This subsequently causes internal stress concentration within the sealant, reducing its adhesion to the coating substrate.