METHOD OF PRODUCING ZIRCONIUM DIOXIDE-BASED CERAMIC FOR RESTORATION DENTISTRY Russian patent published in 2014 - IPC C04B35/486 C04B35/624 

FIELD: chemistry.

SUBSTANCE: method of producing a zirconium dioxide-based ceramic can be used in restoration dentistry. The method provides, from initial reagents in form of aqueous solutions of zirconium oxynitrate (ZrO(NO₃)₂·2H₂O), yttrium nitrate (Y(NO₃)₃·6H₂O), aluminium nitrate (Al(NO₃)₃·9H₂O) and aqueous ammonia solution, combined deposition of zirconium, yttrium and aluminium hydroxides, gel-like residues of which are filtered and frozen at a temperature of minus 20-25°C to form xerogels, which are crystallised at a temperature of 400°C to 500°C. The obtained precursor nano-powders are moulded by double-sided static pressing at 150 MPa without adding a binder and annealing at 1100-1300°C with isothermic ageing for 2 hours, after which the ceramic articles are removed from the furnace and subjected to rapid cooling. The method can be implemented on standard equipment and does not require expensive reagents.

EFFECT: method enables to obtain nano-crystalline powders with the required dimensional homogeneity and chemical purity of the composition, while reducing product synthesis and sintering temperature, as well as duration of the phase formation process.

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