Lateral layer-by-layer nanostructuring of thermal barrier coatings of zirconium dioxide during plasma spraying

Results of experiments on development of the method of the lateral layer-by-layer nanostructuring of coatings prepared by plasma spraying in order to improve their working characteristics under thermal cycling loads are presented. Coating deposition is performed through a mask with holes while maintaining dynamic vacuum in the chamber. Analysis of the morphology of the zirconium-oxide coatings using a scanning electron microscope shows that the structure of the coating obtained in the “shaded” regions almost completely consists of submicron particles and nanoparticles. An estimate explaining the formation of regions in the coating consisting of nanoparticles due to heterogeneous condensation of the vapor phase of the sprayed material in the Prandtl-Meyer expansion formed in the supersonic plasma flow around the barrier is given.