Zirconia-based nanocrystalline material synthesized by directional crystallization from the melt

The effects of composition and growth conditions on structure and properties of ZrO2-(2-5 mol%) Y2O3 PSZ crystals have been studied. The crystals containing 0-35 mol% Y2O3 have been grown by directional crystallization in a cold container. Microstructure, phase composition, density, strength and tribological characteristics have been investigated. An uniform distribution of major constituents of the solid solution was observed, however, local deviations on Y2O3 concentration within ± 0.5 mol% were observed. Morphology of the as-grown facets depends on growth conditions of a cubic single crystal as well as subsequent annealing, which affects phase composition, and formation of specific domain nanocrystalline structure of the tetragonal phase. Mechanical and tribological tests have shown the (2.5-4) mol% Y2O3 PSZ crystals to be the most promising for practical applications.