Synthesis of nanocrystalline boron carbide by sucrose precursor method-optimization of process conditions

Abstract

Nanocrystalline boron carbide powder was synthesized by a precursor method using B2O3 as the source of boron and sucrose as the source of carbon. Precursor was prepared at different temperatures ranging from 300 to 800°C. The optimum temperature for the precursor preparation was found to be 600°C. All the precursors were heat treated at different temperatures from 1000 to 1600°C for different duration of heating, ranging from 5 to 240min under vacuum. The products thus obtained after heat treatment were characterized using X-ray diffraction. The boron carbide obtained was nanocrystalline and the average X-ray crystallite size was found to be ~ 33nm. Boron, total carbon and free carbon contents also were determined. The free carbon content was found to be less than 3% for samples heated at 1600°C for 10min. Effect of heat treatment temperature on the morphology of the synthesized product was studied using scanning electron microscope.