World’s most heat resistant materials identified by scientists

Scientists discovered that tantalum carbide (TaC) and hafnium carbide (HfC) materials are capable of resisting temperatures of nearly 4000 degrees Celsius.

A team of researchers from Imperial College London identified that the melting point of hafnium carbide is the highest ever recorded for a material.

The researchers of the study developed a new extreme heating technique using lasers to test the heat tolerance of the two materials. They used the laser-heating techniques to find the point at which they melted, both separately and as mixed compositions of both.

The study was recently published in the journal Scientific Reports.

Key highlights of the discovery

• Tantalum carbide and hafnium carbide are refractory ceramics, which mean that they are extraordinarily resistant to heat.

• Their ability to bear extremely harsh environments means that refractory ceramics could be used in thermal protection systems on high-speed vehicles and as fuel cladding in the super-heated environments of nuclear reactors.

• However, there has not been any technology available to examine the melting point of the two materials in the laboratory to determine how truly extreme an environment they could function in.

• The researchers of the study found that the mixed compound (Ta0.8Hf0.20C) was consistent with previous research, melting at 3905°C.

• However, the two compounds on their own exceeded previous recorded melting points.

• Tantalum carbide melted at 3768°C while hafnium carbide melted at 3958°C.

Importance of the discovery

• The heat resistance power of the two materials could pave way for them to be used in extreme environments, like in heat resistant shielding for the next generation of hypersonic space vehicles.

• TaC and HfC could potentially be used in nose caps for spacecraft, and as the edges of external instruments that have to bear the most friction during flight.