Carbothermal Reduction Synthesis of Zirconium Diboride Powders Assisted by Microwave

Abstract

ZrB2 powder has been prepared through carbothermal reduction boronization of zirconia/boron carbide/carbon mixtures heating assisted by microwave. The powder characteristics were investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF), nitrogen absorption (BET model) and scanning electron microscope (SEM). The experiments indicated that excessive B4C is necessary and the carbothermic reaction reacts severely at a higher temperature and complete at 1600oC. The crystallite size has ranged from 50-100 nm, according to the calculated surface area. Highest purity of ZrB2 powder, which was synthesized at 1600oC, is 99.67 wt%. The surface area of ZrB2 powder synthesis at 1600oC is 18.33 m2/g. Vibration of temperature should affect the purity of ZrB2, as the sub reaction acted.

Microstructures, solid solution formation and high-temperature mechanical properties of ZrB2 ceramics doped with 5vol.% WC

“…The raw materials used were ZrB 2 powder synthesized through a boron/carbon thermal reaction between ZrO 2 and B 4 200-mesh screen and then placed in a graphite die (37 mm  30 mm) with a h-BN coating. The mixtures were heated to 1650°C and held at this temperature for 30 min, then a pressure of 30 MPa was applied and the furnace was backfilled with argon gas.…”

“…During the past years, there have been lots of progress and developments in the researches on the synthesis of high purity and ultrafine powders [2][3][4], densification process of sintering [5][6][7][8], microstructure tailoring [9,10], characterization of conventional mechanical properties [11,12] and mechanism of oxidation resistance [13].…”