METHOD OF MAKING HEAT-RESISTANT CERAMICS Russian patent published in 2020 - IPC C04B35/486 C04B35/64 

FIELD: technical ceramics.

SUBSTANCE: invention relates to the field of technical ceramics and can be used for production of refractory nozzles, sputtering injectors for metal melts, batchers for continuous casting of steels, crucibles for induction melting of precious metals and industrial alloys, parts subjected to thermal shock at operating temperatures of 1,570–1,800 °C. Method of making heat-resistant ceramics based on zirconium dioxide involves mixing zirconium dioxide with stabilizing additives, annealing, molding and sintering. Additive of stabilizing oxides is carried out by mixing (25–40) wt% of zirconium dioxide partially stabilized with calcium oxide in amount of (4.0–6.0) wt% and having particle size of 8 to 15 mcm greater than 75 %, with (60–75) wt% of zirconium dioxide partially stabilized with magnesium oxide in amount of (2.5–4.0) wt% and having particle size of 2–5 mcm greater than 75 %. Subsequent two-stage sintering is conducted at temperature of 1,700 °C with the cooling from the maximum temperature at (610–650) °C/h to a temperature in range of (1,400–1,000) °C with isothermal exposure for 2–4 hours at a temperature in this range.

EFFECT: improved heat resistance of ceramics based on zirconium dioxide and simplified manufacturing process.

1 cl, 16 ex, 2 tbl