METHOD OF OBTAINING ULTRAX-TEMPERATURE CERAMIC COMPOSITE MB/SiC, WHERE M = Zr, Hf Russian patent published in 2017 - IPC C01B31/36 C01B35/04 C04B35/565 C04B35/571 C04B35/575 C04B35/58 C04B35/624 C04B35/626 C04B35/628 C04B35/632 C22C29/02 C22C29/14 B01J19/10 B82B3/00 B82Y30/00 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a technology for producing oxidation-resistant ultrahigh-temperature ceramic composite materials of MB₂/SiC, where M = Zr and/or Hf with nanocrystalline silicon carbide, which can be used as oxidation, chemical and erosion-resistant materials in air streams at temperatures above 2000°C, for the creation of aviation, space and rocket technology, heating systems, thermal power plants, as well as in nuclear power technologies, in the chemical and petrochemical industries. Method for producing a ceramic composite MB₂/SiC, where M = Zr and/or Hf, characterized by increased oxidation resistance, containing nanocrystalline silicon carbide in an amount of 10 to 65% by volume, is that a solution of a phenol-formaldehyde resin with a carbon weight content of 10 to 40% in An organic solvent in which the zirconium diboride powder and/or hafnium diboride is dispersed by simultaneous mechanical stirring and ultrasonic action, after which tetraethoxysilane is introduced into the resulting suspension in a concentration of 1⋅10^-3 Up to 2 mol/l and a catalyst for the hydrolysis of tetraethoxysilane, followed by hydrolysis of tetraethoxysilane with stirring at a temperature of 0÷95°C hydrolyzing solutions to form a gel, then drying of obtained gel is carried out at a temperature of 0÷250°C and a pressure of 110-41 atm until the mass change ceases, after which the resulting xerogel is thermally treated at a temperature of 400 to 800°C for 0.5÷12 hours in an oxygen-free atmosphere and at a pressure below 1⋅10^-4 atm to form a highly disperse reactive intermediate of composition MB₂/(SiO₂-C), which is further subjected to high-temperature sintering at a temperature of 1600 to 1900°C for 0.1÷2 hours at a mechanical pressure of 20 to 45 MPa.

EFFECT: invention allows to obtain at relatively low temperatures and mechanical pressure ultra ceramic composites having enhanced oxidative stability in air flow, without extraneous impurities phase.

7 cl, 6 dwg, 4 ex