Phase Equilibria in the Si-B-C-N System

Abstract

Literature information on phase equilibria and materials thermodynamics of the quaternary Si-B-C-N system and its binary (Si-B, Si-C, Si-N, B-C, B-N, C-N) and ternary (Si-B-C, Si-B-N, Si-C-N, B-C-N) subsystems are reviewed. Experimental phase diagrams and thermodynamic data are compared with results from thermodynamic calculations according to the CALPHAD method (CALculation of PHAse Diagrams). Calculated thermodynamic functions, different types of phase diagrams and consistent Scheil reaction schemes for the ternary and quaternary systems are presented. The influence of multicomponent phase reactions on the development and application of refractory and hard materials of this system are discussed and a model for the explanation of the thermal stability of Si-B-C-N precursor-derived ceramics is introduced.