Thermodynamics of gas phase carbothermic reduction of boron-anhydride

The upgrading of carbothermic synthesis of the boron-based non-oxide monolithic or composite ceramics powder depends upon the understanding of thermodynamics of carbothermic reduction (CR) of B2O3(l). Analysis of relative dominance of relevant equilibriums in CR of B2O3(l) and the non-stoichiometric computer program for the minimisation of the Gibbs energy of reactions products has been applied to the B–O–C system. Considerably, lower temperature at which the B4C and boron can thermodynamically be obtained as the pure phase depends upon the extent and the mode of gas phase dilution, and upon the Carbon/B2O3 molar ratio in the charge (CBMR).