SYNTHESIS OF BORON NITRIDE NANO-SIZED PARTICLES

摘要

Specimens, made of hexagonal boron nitride, show high chemical resistance when exposed to temperatures over 1200°C. The influence of the chemical content, temperature raising velocity and duration of the thermal treatment on the nanocrystalline boron nitride synthesis is studied in this report. It is aimed at establishing optimum conditions of the [B_2O_3 + urea] reaction to boron nitride. New data have been reported on BN synthesis in the temperature interval 1550―1950°C. Experiments with varying content of powder mixtures are conducted, for best ratio of initial components to be chosen. A mechanism of OSTWALD's ripening is expected to prevail at highest temperature used, resulting in bigger BN-crystallites obtained.