Effect of laser remelting on heat insulation performance of plasma sprayed ZrO₂-20%Y₂O₃ thermal barrier coatings

The influence of laser remelting on properties of ZrO2-20%Y2O3 thermal barrier coatings deposited by APS method on aluminum substrate, such as the microstructure, phase transition and heat insulation performance is investigated. Pulse laser was used for laser remelting of coating surface. The results show that different specific energy of the laser has an obvious impact on the shaping and performance of the coating. The surface roughness increases and the shaping get worse while the specific energy increases. Under suitable low specific energy laser remelting conditions, the surface and section morphology investigated by SEM indicates that laser remelting can eliminate the layer stacking structure and porosity of coating layer. XRD analysis shows that no phase transition occurred during plasma spraying and laser remelting process. The heat insulation test indicates that the heat insulation performance of APS coatings decreased after laser remelting.