Mechanochemical Processing of Nanocrystalline Zirconium Diboride Powder

Nanocrystalline ZrB 2 powder was prepared by mechanochemical processing of a zirconium (II) dihydride–boron mixture with subsequent annealing from 800°C to 1200°C. The crystallite size and morphology of the synthesized ZrB 2 powders were characterized by X ‐ray diffractometry, scanning electron microscopy, and transmission electron microscopy. The effects of annealing temperature on powder particle size and morphology were assessed. At 900°C or above, pure ZrB 2 powder was obtained without trace quantities of residual ZrH 2 . The synthesized ZrB 2 powder particles were spherically shaped, with a crystallite size between 5 and 40 nm. The crystallite size increased with increase of annealing temperature.