A group of scientists from NUST MISIS developed a ceramic material with the highest melting point among currently known compounds. Due to the unique combination of physical, mechanical and thermal properties, the material is promising for use in the most heat-loaded components of aircraft, such as nose fairings, jet engines and sharp front edges of wings operating at temperatures above 2000 degrees C.
During recent developments, the goal of the scientists was to create a material with the highest melting point and high mechanical properties. The triple hafnium-carbon-nitrogen system, hafnium carbonitride (Hf-C-N), was chosen, as scientists from Brown University (U.S.) previously predicted that hafnium carbonitride would have a high thermal conductivity and resistance to oxidation, as well as the highest melting point among all known compounds (approximately 4200 degrees C).
Using the method of self-propagating high-temperature synthesis,the NUSTMISIS scientists obtained HfC0.5N0.35, (hafnium carbonitride) close to the theoretical composition, with a high hardness of 21.3 GPa, which is even higher than in new promising materials, such as ZrB2/SiC (20.9 GPa) and HfB2/SiC/TaSi2 (18.1 GPa).
The material is meant for spaceplanes.