Hafnium carbonitride is a mixed anion chemical compound derived from hafnium, nitrogen, and carbon. It is a material with high thermal conductivity, resistance to oxidation, and a very high melting point. The melting point of the compound exceeds that of hafnium carbide (HfC), which has a melting point of 3927 degC.
As a result of the high melting point, this material is useful in applications that involve high temperatures. For example, this material could be used in combustion chambers in jet engines, supersonic aircraft nozzles, nose fairings, and other applications.
In addition, the new ceramic material has a unique combination of properties. Among them are a high melting point, high impact toughness, and a high level of plasticity. This will allow researchers to study its performance under hypersonic conditions.
To produce the new material, the scientists from NUST MISIS in Russia used an energy-efficient combustion synthesis method. They synthesized different stoichiometric MeCxN carbonitrides by heating the mixture under a nitrogen atmosphere. The resulting material is characterized by a dense oxide film, a porous cracking layer, and a highly porous hafnium nitride phase.
After this, the hafnium carbonitride powder was consolidated with an SPS device. Afterwards, X-ray diffraction patterns were obtained. XRD patterns showed traces of the hafnium nitride and carbon phases.
Hafnium carbonitride has a density of 1.25 g/cc and a mass-to-volume ratio of 1.3. Besides, its purity is 99.9%. Moreover, the material has a C-N ratio of 1.42, and has a submicron grain size.