The effects of different molten salt composition on morphology and purity of ZrB۲ powder obtained via direct molten salt reaction method

Zirconium Diboride (ZrB۲) powder was synthesized at low temperature via a Direct Molten Salt Reaction (DMSR) method. The influence of different salt compositions including eutectic mixture of (KF-NaF), (KF-KCl) and (KCl-NaCl) on the morphology and purity of the reaction products was studied. The obtained samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Furthermore, the formation mechanism of ZrB۲ was investigated by DTA/TG. The results show that alongside eutectic mixture of chloride salt, ZrB۲ powder can be obtained with eutectic mixture of fluoride salt. In addition, obtained ZrB۲ powder without additional salt has hexagonal prism morphology, whereas ZrB۲ particles prepared with eutectic mixture of fluoride salt have higher purity and particle size and hexagonal morphology as well. Synthesized ZrB۲ Powder in chlorofluoride salt has lower particle size and purity and non-uniform morphology. Synthesized ZrB۲ powder is different from starting material in term of morphology and particle size therefore the dissolution–precipitation mechanism may play a dominant role on the synthesis of ZrB۲ during DMSR process.

Keywords:

Zirconium Diboride , Molten Salt , reaction , Low temperature , Composition