Novel structured yttria-stabilized zirconia coatings fabricated by hybrid thermal plasma spraying

Yttria-stabilized ZrO₂ powders with initial sizes of 5–22 mm were chsosen as feedstock for hybrid thermal plasma deposition. At 100 kW RF input power, the microstructures of the deposited coatings varied from mostly sprayed splats to physical-vapor-deposited nanostructures when the powder feeding rate was reduced from 4 to 1 g/min. At a powder feeding rate of 2 g/min, a peculiar layered coating consisting of both structures was deposited at a rate over 50 mm/min, which is promising for the fabrication of next-generation novel thermal barrier coatings.