| Abstract Scope |
Ultra-high temperature ceramics are thermally stable at high temperatures making them desirable for use in extreme thermal conditions, such as those encountered by wing leading edges used in hypersonic vehicles. Hafnium carbide (HfC) is a material that is being investigated for its use in extreme thermal environments, as it maintains its structural stability to temperatures as high as 2200°C. The focus of this poster is to identify the relationship between carbon stoichiometry and heat of formation of HfC. These results will be compared to existing thermodynamic literature on the enthalpies of formation of substoichiometric HfCs. In this study, three substoichiometric HfC compositions were synthesized through spark-plasma sintering. Samples were then characterized through nitrogen/oxygen analysis, carbon/sulfur analysis, XRD, Archimedes, and SEM. The samples were then combusted via oxygen bomb calorimetry to measure the heat of combustion in order to calculate the heat of formation for each composition.
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