SILICON CARBIDE REINFORCED WITH HEAT-RESISTANT FIBRES AND METHOD OF PRODUCING FROM IT HERMETIC THIN-WALL PRODUCTS Russian patent published in 2015 - IPC C04B35/80 C04B35/577 C04B35/573 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: inventions relate to field of composite materials with silicon carbide matrix, intended for operation under excessive pressure under conditions of high temperature load and oxidative medium, and can be applied in chemical, oil and metallurgical industry, as well as in aerotechnics. Silicon carbide, reinforced with long heat-resistant fibres, compatible by coefficient of linear thermal extension with components of matrix, contains free silicon and carbon uniformly distributed by volume of material in quantity to 6 and 15 wt % respectively; with dimensions of separate fragments of silicon not exceeding 10-15 mcm. Part of silicon carbide is represented by nano-sized grains, fibres and tubes. To produce products from said silicon carbide frame from long fibres is formed, pyrocarbon coating is formed on frame fibres, then plastic blank is formed on base of frame and coke-forming binding agent, with carrying out its carbonisation. Pores of carbonised plastic are filled with nano-sized carbon in form of particles, fibres or tubes and is blank siliconising carried out by steam-liquid-phase method by capillary condensation of silicon vapours in interval of temperatures 1350-1500°C at temperature of silicon vapours exceeding temperature of blank by 50-100 degrees; with larger difference between temperature of silicon vapours and blank corresponding to lower temperature on blank and vice versa, after which heating and exposure at 1700-1750°C in absence of claimed temperature difference is carried out.

EFFECT: increase of service term of hermetic products in chemically aggressive media at high temperatures.

6 cl, 5 ex, 1 tbl