Study On Resistance To High Temperature Of Nano-ZrO₂ Ceramic Composite Coating

Nano - zirconia composite ceramic coating is widely used in high temperature coating,because of its high-temperature chemical stability is good ,thermal conductivity coefficient is small and its coefficient of thermal expansion and hardness is higher. In this paper,the effect and mechanism of nano-zirconia in improving the coating microstructure and coating properties were studied. In this paper,the optimal dosage of nano-zirconia and other additives were identified,and prepared the nano-zirconia composite ceramic coating of a good comprehensive properties.This paper has chosen the ZrO2 （54% -62%） + Y2O3 （6%） as the basis of powder materials,zirconia powder particle size ratio of 1（Nano）:3（Micron）,and with the addition of nano-CeO2 （1% -5%）,nano-TiO2 （2% -6%）,micron Cr2O3 （3% -7%）,micron Al2O3 as a supplement.Nano - zirconia composite ceramic coating has been prepared by means of the subsonic speed flame spraying and the foundational layer materials were made by Ni-Cr-Al powder.The microstructures and surface of coatings have been observed by using microscope,SEM and XRD.The mechanical properties and high-temperature performance of coatings had been tested and analyzed.The best proportion of nano-zirconia and other additives has been optimized by adopting orthogonal experiments.The results show that when the nano-zirconia composite ceramic coating chemical composition is 58%ZrO₂ （nanometer to micronmeter is 1:3） +6%Y₂O₃ +3%CeO₂ +5% Cr2O3 +6%TiO2,coating has better comprehensive mechanical properties, thermal shock resistance,high temperature oxidation resistance and smooth surface.This paper has theory significance and reference value for the future study on mechanical properties and high temperature properties of Nano - zirconia composite ceramic coating .