Preparation of refractory metal diboride powder by reducing refractory metal oxide with calcium hexaboride

摘要

This paper provides a new method for preparing refractory metal diboride by reducing refractory metal oxide with Calcium hexaboride (CaB6), which is prepared using B4C and calcium as raw materials. For refractory metal powders (M = Ti, Zr, Hf, V, Nb, Ta, Cr) which are expensive and hard to be produced by a simple route, it is more cost-effective to directly use refractory metal oxide to prepare its boride. After reacting at 1473 K for 4 h, CaB6 and refractory metal oxide could completely react to form MB2, CaO and B2O3. The single-phase product with the particle size of sub-micron was obtained after acidic leaching, filtration and drying. CaB6 could be used as a universal reducing agent to prepare metal boride.