| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to field of obtaining high-melting inorganic compounds, in particular to obtaining composite silicon nitride-based powders by method of self-propagating high-temperature synthesis (SHS), which can be applied as initial raw material to obtain construction and functional ceramics, in automobile and aviation industry for production of elements of internal combustion engines, lining of combustion chambers, separators of high-temperature bearings, turbine blades, in machine-building - plain and rolling bearings, and friction pair. Method of obtaining composite powder based on alpha-phase of silicon nitride by SHS method includes: preparing mixture of powders of silicon, silicon nitride and magnesium or yttrium oxide; placing obtained mixture into closed reactor; filling reactor with nitrogen to required pressure; local inflammation of mixture and synthesis in combustion mode under nitrogen pressure with further removal of target product, with ratio of silicon and silicon nitride in mixture constituting (1÷4-1÷1), content of one of two oxides constituting 3-20 wt %, with synthesis in combustion mode being carried out under pressure 1-5 MPa.EFFECT: invention makes it possible to obtain active to sintering, metastable composite powders with oxide phase of complex composition, based on alpha-phase of silicon nitride, which make it possible to obtain dense, pore-free, fine-grained silicon-nitride ceramics, preserving high strength to temperature 1500°C, by method of hot pressing.3 cl, 1 tbl, 2 ex |
