METHOD OF PRODUCING ARTICLES FROM CORUNDUM ARMOR CERAMICS Russian patent published in 2020 - IPC C04B35/111 C04B35/626 

FIELD: technological processes.

SUBSTANCE: invention relates to production of high-strength refractory articles from corundum. G-00 metallurgical alumina is annealed together with boric acid and converted into α-form of Al₂O₃, and then calcined alumina is divided into two parts, wherein from one part in an unchanged form is immediately prepared charge moulding powder, and the second part is separately built by wet grinding to a specific surface of 30000 cm²/g and dried, eutectic additive is prepared by mixing by wet grinding burnt alumina, silicon dioxide and magnesium oxide, drying the suspension, heat treatment at temperature below the eutectic temperature of 1300°C and grinding, at wet grinding of moulding powder charge from pre-ground burnt alumina, eutectic additive, magnesium oxide, yttrium oxide and bringing the suspension to specific surface area of about 15000 cm²/g, to moulding powder suspension are added of 8% of an additionally grounded α-Al₂O₃ with specific surface area of 30000 cm²/g, adding the process binder, mixing, then drying to moisture content of less than 1% and sieve granulation is performed to determined parameters of granulometric composition, the workpiece is formed by hot pressing at temperature of 165°C, at specific pressing pressure of about 2700÷3000 kgf/cm with holding time of 90 s, annealing is carried out in two stages, wherein the first step is carried out in a high-temperature tunnel gas furnace at temperature of 1580°C under cover, and second stage is carried out in chamber furnace with oxidative medium at temperature 1670°C and holding for 2.5 hours.

EFFECT: technical result is higher values of physical and mechanical properties of ceramic articles.

1 cl, 1 tbl, 2 ex