CUBIC BORON NITRIDE PREPARATION PROCESS Russian patent published in 2006 - IPC C01B21/64 

FIELD: abrasive materials.

SUBSTANCE: invention can be used in preparation of abrasive materials for polishing and blade tools, bands, pastes, low-temperature greases, heat insulation, and cosmetics. A blend briquette is manufactured from homogenous mixture of sodium azide, sodium tetraborate, and magnesium powders at weight ratio 29.7:26.9:43.4 or that of sodium azide, sodium tetraborate, lithium carbonate, and magnesium at weight ratio 24.3:21.1:9.3:45.3, or the same of sodium azide and magnesium diboride at weight ratio 60:40. A briquette made of inflammation composition containing copper oxide, boron, and nitrocellulose at weight ratio 89.9:8.1:2.0 is joined with above blend briquette. Resulting briquette is placed coaxially in shell in the form of two barrels superposed to each other through bottoms bent to 180 degree. Metallic shell with blend and inflammation composition is installed in cavity of heat-and electro-insulation perforated washers with centrally oriented coaxially installed output leads. Loaded container is placed into high-pressure chamber and exposed to pressure 45-47 kbar, after which blend and inflammation composition to temperature of thermodynamic stability of cubic boron nitride at electric power growth rate 30-40 W/sec to the value representing 0.8 specified value corresponding to indicated temperature. The total ensemble is kept for 4 min, cooled, and kept for 1 min at pressure 45-47 kbar, after which pressure is lowered to atmospheric value, synthesis product is withdrawn and subjected to acid enrichment, neutralization, and drying.

EFFECT: reduced power consumption and improved performance characteristics of cubic boron nitride.

6 cl, 1 tbl, 3 ex