Journal of Coating Technology and Innovation

ABSTRACT

The optimization of process parameters was essential when creating YSZ-CeO₂ nanocomposite coatings using atmospheric plasma spraying. Using particle diagnostics, the molten state of nano agglomerates was carefully observed to maintain their nanostructure, including temperature and velocity. The research focused on the microstructure, thermal diffusivity, and adhesion strength of the nanocomposite coatings applied through spraying. FESEM examination uncovered a dual-phase microstructure, with nano-regions embedded in a fully molten particle matrix. The dual structure caused a decrease in the thermal conductivity of nano YSZ coatings, due to phonon scattering at grain boundaries, point defect scattering, and higher inter-splat porosity in comparison to bulk coatings. The addition of CeO₂ played a major role in causing this decrease. XRD analysis verified that tetragonal Zirconia was present, and the average grain size of as-sprayed CeYSZ coatings varied from 90 to 120 nm. The improved thermal and mechanical characteristics were mainly a result of increased interfacial toughness, which was brought about by the existence of adherent nano regions and the dense coating structure. This research showcases the capabilities of YSZ-CeO₂ nanocomposite coatings for use in situations where high thermal and mechanical performance is needed.

Article History

KEYWORDS

1. Plasma spraying
2. Nano zones
3. Phonon scattering
4. Thermal diffusivity
5. Adhesion