Macroscopic Thermodynamic Analysis of Boride and Carbide Ceramics: Processing and Property Implications

Macroscopic thermodynamic analysis based on the principles espoused by J. Willard Gibbs is a powerful tool for understanding phase stability, reaction mechanisms, and oxidation of boride and carbide ceramics. This presentation will review two case studies of thermodynamic analysis of ultra-high temperature ceramics. The first is densification of zirconium diboride ceramics. This analysis revealed identified additives that could react with and remove surface oxide impurities to enhance densification without forming a liquid phase. The second case study will focus on compositionally complex dual-phase ceramics consisting of a combination of boride and carbide phases with different compositions. The second analysis was able to predict metal segregation in dual phase ceramics that was consistent with experimental reports. The presentation will conclude by identifying areas where future research is needed.