| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to inorganic chemistry, namely to obtaining silicon-carbide materials and products, and can be applied as thermal-protective, chemically and erosion resistant materials, used in creation of aviation and rocket technology, carriers with developed surface of heterogeneous catalysis catalysts, materials of chemical sensorics, filters for filtering flows of incandescent gases and melts, as well as in nuclear power industry technologies. To obtain nanostructures SiC ceramics solution of phenolformaldehyde resin with weight content of carbon from 5 to 40% with tetraethoxysilane with concentration from 1·10to 2 mol/l and acidic catalyst of tetraethoxysilane hydrolysis id prepared in organic solvent; hydrolysis of tetraethoxysilane is carried out at temperature 0÷95°C with hydrolysing solutions, containing water and/or organic solvent, with formation of gel. Obtained gel is dried at temperature 0÷250°C and pressure 1·10÷1 atm until mass change stops, after which carbonisation is realised at temperature from 400 to 1000°C for 0.5÷12 hours in inert atmosphere or under reduced pressure with formation of highly-disperse initial mixture SiO-C, from which ceramics is moulded by spark plasma sintering at temperature from 1300 to 2200°C and pressure 3.5÷6 kN for from 3 to 120 min under conditions of dynamic vacuum or in inert medium. Excessive carbon is burned in air at temperature 350÷800°C.EFFECT: obtaining nanostructured silicon-carbide porous ceramics without accessory phases.4 cl, 4 dwg, 3 ex |
