A group out of Missouri University of Science and Technology says it has a new method for mixing metals with ceramic that will allow stronger, heat-resistant, functionally graded materials for the creation of hypersonic and other ultrahigh-temperature aerospace components.

The group, led by Ming Lue, a mechanical and aerospace engineering professor at S&T, uses a precisely controlled extrusion approach to combine – in varying proportions – the ceramic and metallic base components together with a binder. For example, zirconium carbide is pushed through one tube, tungsten is pushed through a second tube and the binder from a third. The metal–ceramic combination is then extruded as a paste, but interesting thing is that the exact mix could be carefully altered as a function of time.

This could potentially revolutionize manufacturing of complex- near net-shaped ceramic parts (which can’t  be processed by conventional methods such as slip casting or injection molding).

In other words, a manufacturer could produce a component with a paste composition that can be varied as it is extruded.

The piece is made depositing the paste, layer-by-layer. The component is then put through what they call Rapid Freeze Prototyping and Freeze Casting to remove the water and polymer binder. The last step is a reaction sintering. The end result is a component composed of gradient materials with custom-tailored mechanical properties.

The biggest benefit, says Leu, who is associated with S&T’s Center for Aerospace Manufacturing Technologies, is the ease it would give manufacturers to create customized parts for aircraft or spacecraft. “By controlling the extrusion forces, we can customize the percentage composition of each of the materials in the final product,” says Leu, who worked on the project with Greg Hilmas, a professor of materials science and engineering  and Robert G. Landers, an associate professor of mechanical and aerospace engineering.

Another benefit is that the process cuts the amount of polymer needed to bind the metal and ceramic.

“In order to create high-performance combustion components or high-performance hypersonic vehicles that can sustain extreme heat and minimize thermal stresses, these types of functionally graded materials will be needed,” says Leu.

University of Queensland (Australia) researchers are testing new materials that can withstand the extreme heat experienced by hypersonic aircraft to enable longer flight times. The tests use scramjet engines composed of composite materials that may be able to withstand the heat produced at Mach 8.

The $1.5 million project is run by Australia’s Defence Materials Technology Centre.

“A scramjet-powered vehicle could fly between London and Australia in two hours, so we’re looking at materials that can survive hypersonic speeds for longer periods,” said project leader Michael Smart, mechanical engineering professor at UQ.

Smart said the research was particularly looking at new materials for leading edges, the parts of the wings that first contact the air.

At hypersonic speeds, air friction causes extreme heating of the leading edges on wings, fins and engine parts. Temperatures on the surface of an object traveling at Mach 5 can reach 1000 °C. These high temperatures cannot be sustained by standard aircraft and turbine materials. At higher speeds the temperatures can be even more extreme. At Mach 8 the temperatures can reach 2700 °C at the leading edge and 3000 °C in the engine combustion chamber.

Another challenging problem area is inside the scramjet engine. The interior must handle a corrosive mix of hot oxygen and combustion products, as well as high thermal, mechanical and acoustic loadings.

Smart is working with ceramic composite materials engineer John Drennan, director of UQ’s Centre for Microscopy and Microanalysis.

“The technologies we are developing will have application anywhere where performance is needed from materials in high temperature environments for long periods,” Drennan says. “Some potential uses for the new materials might include [use] in power plants and for exhaust nozzles of jet engines.”

Rights to a special low-temperature hydration system originally developed by NASA for astronauts - one that makes heavy use of the insulating wonder aerogel – is now being made available for licensing.

In a release from Fuentek LLC, the company announces that the Johnson Space Center has selected it to find prospective licensees for NASA’s High Altitude Hydration System. The major distinction of this system is that it prevents fluids from freezing.

This benefit of such a high-performance system is obvious for the freezing temperatures of space, but mountaineers also need a system that will not freeze in harsh conditions. Thus, Fuentek says it will target the manufacturers of outdoor equipment in commercializing the technology that can be used to use body heat to prevent freezing in tubing, containers and mouthpieces.

Credit for the creation of the NASA system is given to astronaut-mountaineer Scott Parazynski. In a post on the company blog, Fuentek representative Karen Hiser provides details about the hydration system:

“Dehydration is a life-threatening complication for high-altitude climbers,” says Hiser, “The lightweight device will provide 2-3 liters of liquid beverage (water, tea or nutritional supplement) over the course of a full summit day. The straw is insulated with aerogel or other highly efficient insulators, a feature that allows the heating system to work without extra thickness or weight. The technology uses passive transfer of body heat in one option, an intermediate variant system in another and a battery-powered microcontroller in a third.”

“Whether using a hands-free hydration system or traditional, insulated water bottle, virtually every climber and cold-weather athlete has had their water freeze when they needed it most. This new technology provides an alternative to traditional hydration systems and will help prevent the life-threatening complications that accompany dehydration,” says Hiser.

Read more about aerogel:

Aerogel insulation hits housing market

Solar Decathlon entries make use of aerogel

Aeroclay research at Case Western Univ.

NASA’s aerogel grid captures amino acid in space

Cabot”s Nanogel aerogel insulation selected for 50 km of subsea pipelines

Artistic aerogel light demonstrations

Aerogel used in classic car remake

Aerogel’s potential to mop up oil spills

Aerogel has potential as tunable waveplate

Universe’s largest catcher’s mitt?

Birdair demonstrates aerogel membrane roofing systems

Nanotube aerogel sheets - better than real muscle?

Introduction to aerogel video

Hey NASA! I, too, will fill out a questionnaire about your new fancy-dancy Stardust-NExT site if you send me a little chunk of aerogel to play with.

LaserMotive’s photovoltaic-powered machine became the first in the three-year history of NASA’s space elevator contest to climb a 2,953-foot-long ribbon, securing a prize of $900,000.

The competition saw teams use laser-powered robots they designed and built to climb a 1 kilometer-long cable suspended vertically from a hovering helicopter.

LaserMotive fell short of the $2 million grand prize. For that, they would have had to ascend the ribbon with an average speed of 5 meters per second or roughly 11 mph. They didn’t quite reach that goal - they surpassed a secondary goal of 2 m/s – but it appears that scientists are finally making real progress on a concept first proposed in 1895. What’s more, the ground laser that was used to charge the photovoltaic cells used half the power than their previous model with far better results.