New approach for advanced zirconia thermal barrier coatings by plasma-laser hybrid spraying technique

Abstract

Laser treatment improved the thermal shock resistance of Thermal Barrier Coatings (TBCs). Thermal diffusivity measurement revealed that post-treated coatings are not effective for reducing heat flux. However, laser-hybrid sprayed TBCs with segmented feather-like microcracks decreased the thermal diffusivity by 60 percent of the as-sprayed value at specific laser-hybrid conditions. The post-treated TBCs with dense layers showed abrupt collapse of laser-treated layers but hybrid sprayed coatings exhibited improved erosion resistance. And the reliability of TBC with segmented cracks was also confirmed from the cyclic oxidation test. From those investigations, a new approach for manufacturing advanced TBCs by laser-hybrid plasma spraying was suggested.