Investigation of thermal shock resistance of the nanostructured zirconia thermal barrier coatings treated by laser glazing

The nanostructured zirconia coatings were pre-pared using nanostructured zirconia powder by plasma spray process,and then the coatings were treated by laser glazing. The effect of laser glazing process parameters (laser input energy density) on the thermal shock resistance was investigated. It is shown that the thermal shock resistance of coating is significantly changed with the different laser glazing process parameters. Excellent properties of thermal shock resistance can be achieved under optimized process parameters. It is indicated that the microstructures are different while using different process parameters, which results in different thermal shock resistance of zirconia coating. The surface morphology and microstructure of laserglazed coating are beneficial to the release of thermal stress,and the phase composition is stable during thermal shock. It is believed those are responsible for the improvement of thermal shock resistance of zirconia coatings after laser glazing treatment.