METHOD OF MAKING CERAMICS BASED ON ZIRCONIUM DIOXIDE Russian patent published in 2019 - IPC C04B35/486 C04B35/626 C04B35/64 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing ceramics based on zirconium dioxide with a transformable tetragonal crystalline phase and can be used for making wear-resistant parts of a spherical shape, for example, as a milling bead. According to the invention, the base used is a baddeleyite concentrate which is preliminarily milled and mechanically activated by means of a wet high-energy grinding combined with a stabilizer (calcium oxide), a molding suspension is prepared, for which the prepared milling is placed into a mixing container, into which a dispersant, distilled water and aqueous solution of sodium alginate are added, followed by homogenisation of the molding suspension and its degassing. Weight fraction of the baddeleyt powder in the molding suspension ranges from 40 to 60 wt. %, sodium alginate 0.6–1.6 wt. %. Suspension by metering piston device through calibrated nozzle in form of drops is introduced into solution of hardener 1–10 wt. % aqueous solution of calcium chloride, which is held for at least 5 minutes. Balls are extracted from calcium chloride solution, washed in distilled water, dried on filter paper at room temperature throughout the day. Then, the beads are placed in a high-temperature muffle furnace and sintered in an air atmosphere for 4 hours at temperature of 1250–1400 °C with heating rate of 180–300 °C/h, followed by cooling at rate of 180–300 °C/h to temperature 140 °C.

EFFECT: by its mechanical properties obtained baddeleyite ceramics is not inferior to engineering ceramics from chemically precipitated ZrO₂, synthesized from zircon.

5 cl, 4 tbl, 8 dwg