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 B 2O 3(l). Analysis of relative dominance of relevant equilibriums in CR of B 2O 3(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 B 4C 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/B 2O 3 molar ratio in the charge (CBMR).