A novel low thermal conductivity thermal barrier coating at super high temperature

Novel high temperature-resistant thermal barrier coatings are urgently required as the stringent operating environment. High temperature property studies of zirconia matrix thermal barrier coatings doped with Cr3+, Mg2+, Si4+, and Mn4+ ions prepared by solid phase reaction method are reported. The results of X-ray diffraction measurements prove the coatings prepared by air plasma spray are predominately in a non-transformable cubic structure which is the most stable phase structure at high temperature. Hot corrosion tests of molten salts (at 900 degrees C) and oxides (at 1400 degrees C) have been carried out, and the results show that the corrosions lead to the coating surface deterioration. The thermal conductivity of coating doped with Cr3+ is the lowest value until to 1600 degrees C, and the mechanism has been analyzed. The antioxidant ablation results also proved that the coating doped with Cr3+ showed the best heat-insulating property. All the results show that the coating doped with Cr3+ will be a promising thermal barrier coating.