Surface Modification of Thermal Barrier Coatings by Single-Shot Defocused Laser Treatments

Thermal barrier coatings (TBC) consisting of atmospheric plasma-sprayed ZrO 2 -8 wt.% Y 2 O 3 and a high velocity oxygen fuel-sprayed metallic bond coat were subjected to CO 2 continuous wave laser treatments. The effects of laser power on TBCs were investigated as was the thermally grown oxide (TGO) layer development of all as-sprayed and laser-treated coatings after thermal oxidation tests in air environment for 50, 100, and 200 h at 1100 °C. The effects of laser power on TBCs were investigated. TGO layer development was examined on all as-sprayed and laser-treated coatings after thermal oxidation tests in air environment for 50, 100, and 200 h at 1100 °C. Melted and heat-affected zone regions were observed in all the laser-treated samples. Oxidation tests showed a stable alumina layer and mixed spinel oxides in the TGO layers of the as-sprayed and laser-treated TBCs.