ULTRA-HIGH TEMPERATURE AND OXIDATION-RESISTANT COATINGS MADE OF REFRACTORY METAL DIBORIDES AND SILICON CARBIDE ON COMPOSITE MATERIALS Russian patent published in 2022 - IPC C04B41/90 C04B41/87 

FIELD: chemistry.

SUBSTANCE: invention relates to the process of producing ultra-high-temperature oxidation-resistant functional ceramic matrix materials for creating parts with a wide range of application, suitable for operation under extreme high-temperature and oxidating conditions. The process of producing refractory metal diborides modified with silicon carbide is implemented by the CVD method, by thermal gas-phase decomposition of the initial borohydrides of refractory metals (hafnium, zirconium, niobium, and tungsten borohydrides) and methylsilane on the surface of various materials heated to a temperature of 180 to 250 °C when applying refractory metal diborides and 600 to 650°C when modifying with silicon carbide. The process of applying refractory metal diborides (hafnium, zirconium, niobium, tantalum, tungsten) is implemented by passing highly volatile vapours of a solution of a refractory metal borohydride in an inert medium of argon or nitrogen under a residual pressure of the inert medium of 0.8 to 1.3 kPa for 2 hours at a temperature of 180 to 250 °C until a weight gain of the treated material of at least 12% wt. The process of modification with silicon carbide is implemented by passing methylsilane vapours in an inert medium of argon or nitrogen under a residual pressure of the inert medium of 10 to 25 Pa for 4 hours at a temperature of 600 to 650 °C until a weight gain of the treated material of at least 12% wt. and not less than 24% total wt. after applying refractory metal diborides and modifying with silicon carbide.

EFFECT: possibility of increasing the productivity of the technology for producing ultra-high temperature oxidation-resistant functional coatings from refractory metal diborides, increasing the fire and explosion safety of the process.

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