Authors: L.F. Krushinskaya, G.N. Makarenko, I.V. Uvarova, I.I. Timofeeva, L.P. Isayeva
Affilation: Institute for Problems of Materials Science NAS of Ukraine, Ukraine
Pages: 111 - 114
Keywords: nanostructured composites, nitration, boron silicide, boron and silicon nitrides
The process of boron silicide nitration in nitrogen and ammonia media has been studied. The products of nitration were established the composite powders of boron and silicon nitrides. By using the boron silicide compounds instead of boron and silicon powder mixture it can be possible to decrease the temperature of BN and Si3N4 formation up to 1200 and 1400 0C, correspondingly. Without using the catalytic additions, the BN and Si3N4 are generated at 1500 and 1700 0C, correspondingly over a long period of time. Decreasing the temperatures and time of nitration one can increase the dispersity of final products. The nitration by ammonia occurs more intensive than that by nitrogen and the boron and silicon powder nitrides are more dispersive and have the specific surface area about 20 m2/g. The dispersity of BN and Si3N4 composites can be increased by preliminary mechanical activation of boron silicide by intensive milling. In this case the temperature of nitration decreases up to 1100 oC and as a result of this the composite powders of boron and silicon nitrides have a size of particles about 50-70 nm.