The two most heat resistant materials in the world

A new record has been set for the world’s most heat resistant material. Tantalum carbide and hafnium carbide materials have been found able to withstand temperatures approaching 4000°C.

A team from Imperial College London made the discovery, finding that the melting point of hafnium carbide in particular is the highest ever to be recorded. This may have interesting applications in various fields including heat resistant shielding for new generations of hypersonic aircraft and space vehicles. Due to the extreme heat resistance of these materials they could also be used in the super heated environments found in nuclear reactors.

This discovery is a result of new technologies being able to test the melting points of ever-greater heat resistant materials in laboratory settings. The Imperial College team used a new extreme laser-heating technique to test tantalum carbide and hafnium carbide as well as mixed compositions of both these materials. It was previously believed that a mixed composition of both had the greatest heat resistance at 3905°C. But with the newly developed heating technique, it was found that tantalum carbide and hafnium carbide melt at 3768°C and 3958°C respectively.

Dr Cedillos-Barraza at Imperial’s Department of Materials carried out the research. Whist not previously used for such a purpose, he has suggested that given their extreme heat resistance, these materials could well have applications in aircraft that reach speeds greater than Mach five and thus generate high amounts of heat from friction. This could also have implications for the development of spacecraft capable of taking off from ground level and entering orbit. These would require a high heat resistance to withstand the extreme temperatures generated from exiting and re-entering the atmosphere.

Hypersonic aircraft and spacecraft are generating greater interest with the success of private space companies like Space-X. However, more advanced materials are required to produce the vehicles necessary for multiple trips at high velocity or into space. With the discovery of these new compounds, the tantalising prospect of space tourism or higher speed aircraft may finally be within reach.