Synthesis of Highly Dispersed Zirconium Diboride for Fabrication of Special-Purpose Ceramic

摘要

Reduction of zirconium dioxide with boron carbide and nanofibrous carbon in argon yielded a highly dispersed powder of zirconium diboride. Characteristics of zirconium diboride powders were examined by various analytical methods. The material obtained is represented by a single phase, zirconium diboride. Powder particles are for the most part aggregated. The average size of particles and aggregates is 10.9-12.9 mu m with a wide size distribution. The specific surface area of the samples is 1.8-3.6 m(2) g(-1). The oxidation of zirconium diboride begins at a temperature of 640A degrees C The optimal synthesis parameters were determined: ZrO2: B4C: C molar ratio of 2: 1: 3 (in accordance with stoichiometry), process temperature 1600-1700A degrees C, synthesis duration 20 min.