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

Abstract

Abstract In the present study, a combined modeling and experimental approach were chosen to compare the carbothermal reaction mechanisms of TiO 2 with B 2 O 3 or B 4 C and to obtain a high yield of TiB 2 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 TiB 2 synthesis were investigated at fixed initial molar ratios of TiO 2 :B 2 O 3 :C (1:1:5) and TiO 2 :B 4 C: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 B 2 O 3 was used as starting material. Full conversion to TiB 2 was obtained at 60 min and 1600 °C for both initial sources of boron.