Special Features of Preparation of Nanosized Zirconium Diboride Powders of Various Dispersity

摘要

Products of the zirconium powder reaction with amorphous boron in a Na2B4O7 ionic melt at 650-850 degrees C and those of the ZrCl4 reaction with NaBH4 at 300-725 degrees C have been studied by means of X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry, and elemental analysis. At temperature >= 750 degrees C, single-phase ZrB2 with the particle size of 60-80 nm is formed in a Na2B4O7 ionic melt, whereas the ZrB2 powder obtained via the reaction of ZrCl4 with NaBH4 at temperature >= 575 degrees C consists of particles differing in the shape, some of which are close to spherical with diameter of 10-35 nm.