In a breakthrough, scientists have found most heat resistant material in the world which might improve the heat shielding of the spacecraft and also it might come handy in several other areas of scientific experiments. The new material can withstand temperatures of up to 4,000 degrees Celsius with ease.
A team of researchers from the Imperial College of London discovered the heat resistant ability of refractory ceramics named Tantalum carbide (TaC) and hafnium carbide (HfC), and their ability to withstand extremely harsh temperatures which might come handy in manufacturing heat shield for the very fast moving objects like spacecraft and as fuel cladding in the super-heated environments of nuclear reactors.
According to scientists, these materials have very high melting point of over 4000 K, but researchers cannot test it as they cannot create such harsh environments in any lab. Still, study authors tested the materials by bombarding laser and found that the materials started melting in the range of 4041–4232 K. HfC was found to be more heat resistant when compared to TaC.
For the study, researchers had to develop a new heating technique using laser or else they couldn’t have tested the endurance of these ceramic materials. Researchers are calling it a breakthrough as it will aid in several areas of science and technology.
“The friction involved when travelling above Mach 5 – hypersonic speeds – creates very high temperatures. So far, TaC and HfC have not been potential candidates for hypersonic aircraft, but our new findings show that they can withstand even more heat than we previously thought – more than any other compound known to man. This means that they could be useful materials for new types of spacecraft that can fly through the atmosphere like a plane, before reaching hypersonic speeds to shoot out into space. These materials may enable spacecraft to withstand the extreme heat generated from leaving and re-entering the atmosphere,” said Dr Omar Cedillos-Barraza, who is currently an Associate Professor at the University of Texas.
Dr Cedillos-Barraza added: “Our tests demonstrate that these materials show real promise in the engineering of space vehicles of the future. Being able to withstand such extreme temperatures means that missions involving hypersonic spacecraft may one day be manned missions. For example, a flight from London to Sydney may take about 50 minutes at Mach 5, which could open a new world of commercial opportunities for countries around the world.”
Researchers are developing hypersonic vehicles that have very sharp and pointy tips to improve aerodynamics and extreme heating produced due to very high speed can melt nose tips causing aircrafts to crash. Scientists say that temperatures can cross over 2200k when moving faster than 5 Mach. Thus, we need materials that have extremely high melting point will not melt even at very high temperatures. It has led to the researcher and developement of high temperature materials, including a group of ceramics commonly known as ultra-high temperature ceramics (UHTCs). UHTCs have melting temperature over 3300K which is well above the 2200k mark.
Tantalum carbide (TaC) and hafnium carbide (HfC) have even higher melting points (over 4000 K) which are the highest reported among all known inorganic materials. They are known to form a continuous solid solution over the whole range of compositions.
Laser heating experiment consisted of four consecutive laser pulses, starting with a low-power pulse held for a long hold time (typically 1000 ms), and then the power of the subsequent pulses were increased but shortened in hold time (typically few hundreds ms). The pre-heating stage and the successive pulses were conceived to minimise thermal stresses and the risk of mechanical failure of the samples.
The results from this work show that HfC0.98 has the highest melting point in the TaC-HfC system at (4232 ± 84) K, which make it the highest melting point compound, since the melting temperature of TaC was experimentally found to be lower than HfC in this work.Scientists at NASA are also struggling to develop heat shield for the Orion spacecraft that will carry humans on Journey to Mars. Now, the new study has paved the way for developing a better heat shield that will ensure
Scientists at NASA are also struggling to develop heat shield for the Orion spacecraft that will carry humans on Journey to Mars. Now, the new study has paved the way for developing a better heat shield that will ensure safety of astronauts aboard the spacecraft.
The study appeared in the journal Scientific Reports.Tags: heat shield, Material, Science, spacecraft, temperature