Synthesis of Boron Nitride powder by carbothermal method, using phenolic resin and carbon black and investigating the effect of additive of calcium carbonate

Effect of CaCO3 on carbothermic formation of hexagonal boron nitride (h-BN) was investigated. B2O3–C mixtures containing CaCO3 additive were reacted at 1500   for 120 min in nitrogen atmosphere. Formed phases in the reaction products were determined by powder-XRD analyses, and amounts of the constituents were determined by chemical analyses. Particle size and morphology of the formed h-BN powders were examined by SEM. It was found that the use of resin instead of carbon black increased the amount of boron nitride formed and decrease grain size of h-BN significantly. The average particle size with black carbon was about 200–350 nm, On the other hand, the average particle size with resin is about 90-170 nm. In this paper, the amount of boron oxide was also variable, which increased as the amount of boron nitride produced increased and then remained almost constant.