Researchers have perfected a substance which can bear extremely high temperatures in the order of 4000 degrees centigrade. Scientists affiliated to the Imperial College London have identified material “Hafnium Carbide” which has the highest melting point recorded for any substance. It can pave the way for the design of better heat resistant shielding for space vehicles which have to endure very high temperatures during re-entry into the Earth’s atmosphere.
Potential uses of the material could be in Nose cones of spacecraft, edges of instruments which have to withstand frictions during flight, external covering of vehicles which travel in excess of Mach 5, etc.
Refractory ceramics are made of materials which are resistant to extremely high temperatures and harsh environments. Tantalum carbide (TaC) and hafnium carbide (HfC) are refractory ceramics, and they have the potential of use in thermal protection on supersonic and even hypersonic vehicles. It also has the potential for use in nuclear reactors.
Researchers were at a loss after perfecting the substance since testing the material in temperatures of such high degree was not possible. The scientists developed an extremely high-temperature process using lasers and tested the heat resistance of the substance. Tests revealed that mixing the two carbides raised the heat tolerance levels to almost 4000 degrees as expected. Even the individual components far exceeded the melting point of any substance previously known.
Space crafts and capsules like the Progress Space Vehicle endure extremely high temperatures on re-entry into the atmosphere. Hypersonic speed leads to extremely high frictional heat when the surface of the spacecraft rubs against the air molecules. The American Space Shuttle had heat-resistant tiles on its underbelly which protected the occupants of the Space Shuttle.
Any anomaly in this protective envelope can be disastrous as was the case with the Columbia disaster. Russians have perfected a crude method of protection where the insulating material burned slowly thus protecting the inmates of the vehicle. However, this is an expensive method, and the vehicle cannot be used again. The latest material will have wide use in all forms of future space vehicles.
