Synthesis of Monodispersed Fine Hafnium Diboride Powders Using Carbo/Borothermal Reduction of Hafnium Dioxide

Fine hafnium diboride (HfB 2 ) powders have been prepared by modified carbothermal/borothermal reduction of hafnium dioxide (HfO 2 ) at relatively low temperatures (1500°–1600°C) for 1–2 h. The XRD patterns could be indexed as hexagonal HfB 2 and no evidence of HfC, HfO 2 , or other impurities was observed. Glow discharge mass spectrometer analysis indicates that the synthesized HfB 2 powders had high purity. The synthesized HfB 2 powders had small average crystallite size (around 1 μm) and low oxygen content (<0.30 wt%). Scanning electron microscopy observation of the as‐prepared powders demonstrated quasi‐column morphology and laser particle size analysis showed monodispersity (polydispersity 0.005).