Preparation of Zirconium Diboride Powder by Carbon Thermal Reduction Method

摘要

Zirconium diboride (ZrB_2) powders with no impurities were prepared using zirconium oxide (ZrO_2), boron carbide (B_4C) and carbon black as raw material by carbon thermal reduction. The phase composition of ZrB_2 powders was characterized by X-ray diffraction (XRD) and the micro-morphology was observed by scanning electron microscope (SEM). The effects of B_4C content, calcination temperature and holding time were studied on the formation of ZrB_2 powders. The results indicated that ZrB_2 powders could be successfully synthesized while holding for 1.5 h at 1600°C in Ar atmosphere. When the content of B_4C was 17.7 wt%, there existed the crystal phase of ZrB_2 only. The impurities could be easily led in with the increase of content of B_4C. ZrB_2 powders with the size from 1-5 μm could be obtained eventually and the particle size grew obviously with increase in the holding time.