Thermite assisted synthesis of ZrB2 and ZrB2-SiC through B4C reduction of ZrO2 and ZrSiO4 in air

ZrB2 and ZrB2-SiC powders have been produced by reducing ZrO2 and ZrSiO4 with B4C without using any furnace. Magnesium was added to the mixtures of (ZrO2+B4C) and (ZrSiO4+B4C). The reaction has been assisted by a floral thermite packed around the compacts. By introducing elemental Si into (ZrO2+B4C) mixture, composite powders of ZrB2-SiC formed. After leaching out MgO with suitable HCl water solution, the product was analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of Si, B4C, and Mg on the extent of formation of ZrB2, ZrB2-SiC, and other phases has been studied. Formation of nano-sized ZrB2 and ZrB2-SiC composite powders was identified. The adaptability of the process for bulk production was examined.