SILICON NITRIDE-BASED COMPOSITE POWDER Russian patent published in 2015 - IPC C01B21/68 

FIELD: chemistry.

SUBSTANCE: invention relates to field of obtaining refractory inorganic compounds, in particular to obtaining silicon nitride-based composite powders, which can be used as initial raw material for manufacturing construction and functional ceramics, in automobile and aviation industry for production of elements for internal combustion engines, lining for combustion chambers, separators of high-temperature bearings, turbine blades, in machine-building - plain and rolling bearings, friction pairs. Silicon nitride-based composite powder, obtained by CBC method, contains more than 90 wt % of silicon nitride alpha-phase and one or several oxide-containing compounds from group Mg₂SiO₄, Y₂SiO₅, YNSiO₂, Y₂Si₃O₃N₄, YSiO₂N, Y₄Si₂O₇N₂. Said powders are represented by particles with size not larger than 2 mcm, content of admixtures does not exceed 0.5 wt %, specific area of composite powders after deagglomeration of synthesised substance constitutes not less than 6 m²/g.

EFFECT: invention makes it possible to obtain composite powders with increased content of alpha-phase, which do not contain magnesium and yttrium chlorides and fluorides.

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