Scientists have made yet another stride towards making hypersonic aircraft a reality. A new ceramic material has been developed by the Powder Metallurgy Institute at Central South University and is being tested in Manchester.
It is produced using Reactive Melt Infiltration (RMI), a technique which involves the use of a composite made of different types of carbon, penetrated by elements like zirconium, boron, and titanium into a matrix made of a composite of different types of carbon.
Mankind's quest for speed has not been quenched ever since the invention of the wheel, in every sphere. Engineers have always been pursuing the development of the fastest car, truck, ship, and even aircraft. When the first aircraft were built, engineers set out to develop supersonic aircraft, and since supersonic aircraft became a reality, the pursuit of hypersonic aircraft began.
The term Hypersonic is used to refer to speeds above Mach 5 (5,975 km/h), and so far only one aircraft has been able to achieve it so far - The X-15, an experimental aircraft developed by NASA, which touched Mach 6.70 (7,200 km/h). The North American X-15 was used as a research aircraft, flying at extremely high altitudes and extremely high speeds to gather data to be used in space research.
The X-15 had achieved a lot way back in the 1960s including three records for the highest manned flight and fastest manned flight, which stand unchallenged, to this day. However, there was one problem faced by the X-15 and by all other strides towards the development of hypersonic aircraft - the heat developed because of the friction with air at such high speeds.
It is this very problem that this team of scientists had intended to solve. The Ultra High Temperature Ceramics (UHTCs) they are working on, are less prone to oxidation, as the protective layer used by them does not wear off easily at high temperatures and friction.
The magic ingredient apparently is a new carbide coating that, according to the scientists is 12 times better than UHTCs like zirconium carbide (ZrC) currently in use and can survive temperatures as high as 3,000 degrees Celsius (the temperature of the surface when making contact with air at Mach 5).
Usually, high temperatures would erode the protective elements and leave the remaining ceramic vulnerable to the elements (high-speed air), but RMI makes the ceramic harder and resistant to surface degradation at hypersonic speed induced temperatures.
Now that a material which can withstand hypersonic speeds without melting or warping wing edges, nose tips, turbine blades, etc. has been developed, it is just left to engineers now to develop engines which can push aircraft to hypersonic speeds. The X-15 used rocket engines, so would we look back a few decades for hypersonic propulsion, or would engineers develop a new propulsion technology, is something only time can tell.