Synthesis of nanosized zirconium diboride powder via oxide-borohydride solid-state reaction

A novel solid-state reaction was investigated to achieve nanosized ZrB2 particles using ZrO2 and NaBH4 as starting materials, which were dry mixed and thermally treated at increasing temperatures and B:Zr molar ratio to get a complete oxide to boride conversion. X-ray diffraction analysis showed that the reaction was completed after 30 min at 900 degrees C. Field-emission scanning microscopy revealed ZrB2 particles with dimensions around 100 nm. In this paper for the first time we propose the oxide-borohydride system as an alternative to synthesize metal borides to chemical and borothermic reactions. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.