Synthesis of TiB2 by extended arc thermal plasma

Abstract

Synthesis of titanium diboride powder has been systematically investigated by reacting a mixture of TiO2, B2O3 and activated charcoal powder in an extended arc thermal plasma reactor using graphite electrodes in flowing Ar atmosphere. The influence of carbon content on the formation of TiB2 was studied. The product obtained after reaction was subjected for compositional as well as microstructural analysis using XRD, FESEM, Raman and FTIR. From the XRD results, it was observed that TiB2 formation was observed along with TiC indicating notably influence of carbon content and reaction time. The results also confirm the synthesis of TiB2 is based on a TiC formation mechanism. It was also observed that increasing carbon content and reaction time had an obvious effect on the disappearance of unwanted phases. With increase in carbon content to 10 wt% excess and the reaction time for 20 min, the unwanted phases were completely removed and consequently a single-phase titanium diboride powder with crystallite size of about 78 nm was formed.