Preparation of zirconium diboride ceramics by reactive spark plasma sintering of zirconium hydride–boron powders

Monolithic ZrB2 ceramics were prepared by reactive spark plasma sintering of a ZrH2–B mixture at 1650–1800 °C. The microstructure of the resulting ZrB2 ceramics were characterized by X-ray diffractometry and scanning electron microscopy. The ZrH2–B mixture converted completely into ZrB2 without trace quantities of residual ZrH2 and B. Highly dense ZrB2 was obtained at 1750 °C or above. The elastic moduli, flexural strength, thermal and electrical conductivities were comparable with those of ZrB2 ceramics obtained by sintering conventional ZrB2 powders.