On the Ternary System Hafnium-Boron-Carbon

Phase equilibria in the Hf-B-C system were calculated by thermodynamic modeling. The liquid phase was described as a substitutional solution using the Redlich-Kister formalism for the excess Gibbs energy and a reaction scheme was constructed for the entire ternary system. With respect to the increasing technological interest in dense ceramic parts HfB2-"B4C" with various degrees of 10B/11B enrichment as nuclear reactor control or moderator substances, we focus in this paper on the phase relations pertinent to the fabrication of HfB2-"B4C" ceramic material