Novel synthesis of ZrB2 powder by low temperature direct molten salt reaction

Abstract Zirconium diboride (ZrB 2 ) powder was successfully synthesized at low temperature via a novel direct molten salt reaction (DMSR) route using K 2 ZrF 6 , KBF 4 and Al. The influence of temperature (600–900 °C), reaction time (1, 2 and 4 h) and molar ratio of Al/salt (1, 2 and 10) on the morphology and purity of the product was studied. The obtained samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The average size of ZrB 2 particles is more than 1 μm with hexagonal plate-like morphology. The role of Al is crucial for synthesis of ZrB 2 and the yield of product depends directly on the Al content. Results in terms of purity and morphology of the products reveal that a temperature of 800 °C, a reaction time of 2 h and a 10:1 M ratio of Al to salt were the optimum synthesis conditions. Under these conditions, hexagonal plate-like ZrB 2 powder was synthesized.