PREPARATION OF ZIRCONIUM BORIDE POWDER

An intermediate reaction in the synthesis of ZrB2 powder by the reduction of ZrO2 with B4C and carbon was confirmed through both thermodynamical calculation and experimental results. Because the intermediate product B2O3 was volatile, excess boron should be added to compensate for the boron loss in order to prepare high-purity ZrB2 powder. The synthesis temperatures of the intermediate reaction and carbothermic reduction were, respectively, about 1400 and 1600 degrees C, obtained by experiments. The influence of processing temperature and time on the purity and the particle size of ZrB2 powder was also investigated.