Synthesis of TiB2 powders by borothermal and carbothermal reduction of TiO2

Abstract

Titanium diboride powders were synthesized from TiO2 following different reduction methods at temperatures range from 1000 to 1400?C for 1h under flowing argon gas. The reduction processes used in this study are classified as TiO2 + B (borothermal reduction), TiO2 + H3BO3 + C (carbothermal reduction) and TiO2 + B + C (combined reduction). XRD peaks of TiO2 phase are present for each sample below 1100?C. It was also observed that XRD peaks of TiO2 disappeared and TiB2 was formed in borothermal and combined reduction methods at temperature of 1100?C and above. In the carbothermal method, TiBO3 and TiC phases were present at these temperatures and TiB2 could only be obtained after heat treatment at 1400?C. However, this temperature also caused considerable particle growth and formation of the powders with hexagonal shape morphology. The powders synthesized by the carbon-containing reduction process contained residual carbon.