Thermochemical modeling and experimental studies on the formation of TiB₂ through carbothermic synthesis from TiO₂ and B₂O₃ or B₄C

In the present study, a combined modeling and experimental approach were chosen to compare the carbothermal reaction mechanisms of TiO₂ with B₂O₃ or B₄C and to obtain a high yield of TiB₂ as a final product. A thermochemical modeling software, FactSage, was used to estimate the possible products and their quantities by means of Gibbs Energy Minimization approach. In the experimental step, different reaction temperature (1400–1700 °C) and time (0–60 min) combinations on TiB₂ synthesis were investigated at fixed initial molar ratios of TiO₂:B₂O₃:C (1:1:5) and TiO₂:B₄C:C (1:0.5:1.5). The experimental products were characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and BET analysis methods. It was found that calculated modeling results obtained through FactSage agree well with the experimental results. The Magneli phases formed as intermediate products only when B₂O₃ was used as starting material. Full conversion to TiB₂ was obtained at 60 min and 1600 °C for both initial sources of boron.