STRUCTURAL AND MECHANICAL PROPERTIES OF A COMPOSITE MATERIAL BASED ON PARTIALLY STABILIZED ZIRCONIUM DIOXIDE DOPED WITH MAGNESIUM ALUMINATE SPINEL

Ceramic materials based on zirconia (ZrO2) are high-tech raw materials for structural products used in various fields of technology. ZrO2 has a wide range of application due to its unique strength characteristics, chemical resistance and fire resistance. However, the disadvantage of zirconium ceramics is low resistance to thermal shock, which limits its use in products functioning in conditions of frequent temperature changes. In this paper, we consider the possibility of increasing the resistance to thermal shock of ceramics based on zirconium dioxide, due to the introduction of an aluminum-magnesium spinel additive (MgAl2O4).

Nano-Structured Crystals of Zirconium Dioxide for Extreme Applications

The paper discusses application possibilities of nanostructured crystals of partly stabilized zirconium dioxide in greaseless running of plain bearings in order to support normal operation of friction joints at high temperatures and in aggressive conditions. This issue is a burning one in different industries, e.g. circulating pumps in nuclear power engineering, mixing units of crystal synthesizing lines in chemical engineering; motors in space-based targets, rotors of guide blades in axial compressors of airplane engines, supports of high-speed gas centrifuges. Micro-hardness was investigated, and friction surfaces were explored using methods of X-ray, electron-microscopic and element analysis to find a wear mechanism for crystals ZrO2- Y2O3. The paper reports on tribological properties of partly stabilized zirconium dioxide crystals and prospects of their industrial usage.

Sintering and properties of dioxide of ceramics containing the sodium silicate additive

The dependences of the formation of the microstructure and the phase composition of ceramics based on partially stabilized zirconium dioxide on the sintering temperature and the content of the sintering additive are established. It is shown that the introduction of an additive, which forms a low-temperature melt based on sodium silicate - Na2SiO3, leads to a decrease in the sintering temperature by 200 °C. As a result of the work, were obtained dense nanocrystalline materials with a crystal size of 100-200 nm, flexural strength up to 600 MPa and a sintering temperature of 1200-1250 °C.