Physicochemical Processes of Fabricating Ceramic Materials Based on Nanopowders of Zirconium, Yttrium, Cerium, and Aluminum Oxides

When studying nanoceramics, it is necessary to constantly keep in mind the closest interrelation of their fabrication method, structure, and properties. Nanoceramic materials are used in various branches of technology as structural and functional materials. Nanoceramics are also widely used in medicine. They are harmless, stable, and have great affinity to living organisms. ZrO₂-based nanoceramics have a lower elastic modulus than other oxide materials. The specificity of their application lies in their high rupture strength, thermal shock resistance, and chemical stability at high temperatures. However, it is necessary to solve the problem of increasing the fracture toughness of ZrO₂-based ceramic materials. The complex alloying of ZrO₂ with yttrium and cerium oxides and the use of the Al₂O₃ additive leads to an increase in the fracture toughness and lowering of the negative effect of materials in the biological medium. In this work, the physicochemical properties of ceramic powders and materials of the ZrO₂–2Y₂O₃–4CeO₂–Al₂O₃ system synthesized by the chemical deposition of inorganic precursors when applying the sol-gel technology are considered based on scientific data and experimental studies. Alloying pure zirconium oxide by stabilizing Y₂O₃ and CeO₂ oxides and thermal hardening of Al₂O₃ ensure the conservation of the tetragonal structure at room temperature, which makes it possible to retard and control the crack resistance of the material under the load. Investigations into the influence of the sintering temperature and aluminum oxide content on the microstructure and grain size, as well as physicomechanical properties of ceramic materials of compositions ZrO₂–2Y₂O₃–4CeO₂ + 1 wt % Al₂O₃ and ZrO₂–2Y₂O₃–4CeO₂ + 3 wt % Al₂O₃, are carried out.