Effect of addition of tartaric acid on synthesis of boron carbide powder from condensed boric acid–glycerin product

Abstract

The effect of the addition of tartaric acid on the synthesis of boron carbide (B4C) powder from a condensed boric acid (H3BO3)–glycerin product was investigated in this study. The condensed product was prepared by dehydration condensation after directly mixing equimolar amounts of H3BO3 and glycerin with the addition of 0–50mol% tartaric acid (based on glycerin), which was followed by thermal decomposition in air to obtain a precursor powder from which excess carbon had been eliminated. The dispersion state of the boron oxide (B2O3) and carbon components in the precursor prepared from the condensed product with 25mol% tartaric acid added was finer than that without tartaric acid added, in which both precursors had a three-dimensional bicontinuous B2O3/carbon network structure. The complete formation of crystalline B4C powder was achieved at 1250°C within a shorter heat treatment time for the precursor with a fine dispersion state. The synthesized B4C powders became fine owing to the increased number of nucleation sites.