The Influence of Magnetron Sputtering Conditions on the Structure of Heat Resistant ZrO <sub>2</sub> Nanostructured Coatings
The article describes the process of obtaining nanostructured stabilized zirconia dioxide Zr (Y, Hf)O <sub>2</sub> coatings by magnetron RF-sputtering of a ceramic target. The coatings have a two-phase structure consisting of monoclinic and tetragonal dioxide modifications. It is shown that the partial oxygen pressure in the vacuum chamber affects the phase ratio. In particular, an increase in the oxygen pressure (from 0.23 Pa to 0.65 Pa) leads to a significant increase of the monoclinic phase volume fraction in the sputtered coating (from 15 % to 85 %). The grain size in the forming nanostructure is sensitive to the amount of oxygen only at low partial pressures (less than 0.35 Pa). The formation of the single phase (tetragonal) structure in the coating occurs after annealing at the temperature of 1100 °C or higher, while the nanostructure of the material is preserved. The transition to the single-phase structure is accompanied by an increase in the coating micro hardness.