Scientists have identified materials that can withstand temperatures of nearly 4,000 degree C, an advance that has paid the way for heat resistant shielding for the faster than ever hypersonic space vehicles.
Researchers from Imperial College London in the UK discovered that the melting point of hafnium carbide is the highest ever recorded for a material.
Tantalum carbide (
TaC) and Hafnium Carbide (
HfC) are
refractory ceramics, meaning they are extraordinarily resistant to heat.
Their ability to withstand extremely harsh environments means that these could be used in thermal protection systems on high-speed vehicles and as fuel cladding in the super-heated environments of nuclear reactors.
What was lacking till now was technology to test the melting point of TaC and HfC in the lab to determine how truly extreme an environment they could function in.
The researchers developed a new extreme heating technique using lasers to test the heat tolerance of TaC and HfC.
They used the laser-heating techniques to find the point at which TaC and HfC melted, both separately and as mixed compositions of both.
They found that the mixed compound (Ta0.8Hf0.20C) was consistent with previous research, melting at 3,905 degrees Celsius, but the two compounds on their own exceeded previous recorded melting points.
The compound TaC melted at 3,768 degrees Celsius, and HfC melted at 3,958 degrees Celsius.
Spacecrafts could become faster than ever with the next generation of hypersonic vehicles. Friction involved while travelling above Mach 5 hypersonic speeds creates high temperature. Hafnium carbide can withstand such heat.
These materials may enable spacecraft to withstand the extreme heat generated from leaving and re-entering the atmosphere.
Hafnium Carbide- Formula: HfC
- Molar mass: 190.5 g/mol
- Melting point: 3,900°C
- Density: 12.2 g/cm³
- Appearance: Black odourless powder
