METHOD OF MAKING CORUNDUM CERAMICS Russian patent published in 2020 - IPC C04B35/111 C04B35/638 C04B35/64 

FIELD: electrical engineering.

SUBSTANCE: invention relates to production of materials for electronic equipment, such as parts of microwave equipment, in particular, complex profile ceramic frames for microchips. Method of making corundum ceramics involves wet grinding of alumina, introduction of mineralizing additives, obtaining a sinter, milling it, molding and annealing the ceramics. Mineralizing additives are added to the ground alumina in the form of pre-mixed aqueous solutions of MgCl₂ and AlCl₃, the obtained mixture is stirred for not less than 1.5 hours, then mineralizing additives are added in form of a pre-mixed aqueous solution of CaCl₂ and an aqueous suspension of SiO₂ powder with subsequent stirring for at least 1.5 hours. Molding is carried out by hot-molding under pressure of a thermoplastic suspension prepared from ground sinter and paraffin ligament. Paraffin binder is removed by soaking in soot in oxidative atmosphere at temperature of 1,150–1,250 °C for at least 2 hours. Pottery is fired in a vacuum at temperature of 1,600–1,650 °C for 2–3 hours at stepped rise and fall of temperature.

EFFECT: ceramic articles obtained using the present method have low tgδ, high density (99 % of theoretical) and zero water absorption.

8 cl, 2 ex