Research in space has yielded many great inventions and discoveries such as modern battery technology, the tv satellite dish, ear thermometers, the space pen, and many more. Still its potential is oft forgotten as researchers search for cheaper, seemingly easier Earth-researched solutions.
However, some researchers in the field of metallurgy are turning back to space as a source of potential groundbreaking advances. Championing this effort is the program IMPRESS (Intermetallic and Material Processing in Relation with Earth and Space Solidification) run by the European Space Agency (ESA). The programming is investigating the effects of microgravity on the formation of metals at an atomic scale.
Among the materials they are investigating is the potent catalyst raney nickel. The porous nickel compound is a potent catalyst used in fuel cells as a replacement to more expensive platinum. One gram of the compound can have an effective surface of tens of square meters. The IMPRESS program leaders hope that by investigating the formation of variants of this and other materials at low gravity they can dramatically improve a number of fields.
While catalysts like raney nickel are one researched area, researchers also are interested metals for structural industrial applications that are strong and light. While this sounds like two radically different fields of research, ESA project leader, Dr David Jarvis says it’s really not. He states, "They sound like two completely different areas, but they both employ what are known as 'intermetallics' which are similar to alloys but are different in that they are actually chemical compounds, in the same way that water is a compound."
Among the materials investigated is intermetallic titanium aluminide, which is both very strong and very light. Dr. Iles, an ESA researcher explains the critical problem, stating, "[Titanium aluminide] is easy enough to make but we have a stumbling block which is oxidation at high temperatures. What happens is that the oxygen starts to creep in at the surface and what this does is form small cracks which can lead to larger cracks in a process we call embrittlement."
If the problem could be solved, it would invaluable to the creation of airplane turbine blades and other metallic devices. Dr. Iles and his team have found a potential solution in adding tantalum and niobium to the mix. The mix only works in microgravity (environments with low gravity such as space). The researchers found that while the tantalum and niobium leave the mixture when the metal is formed in Earth gravity, when the pull of "up" and "down" is removed, they even distribute themselves. The initial results look very promising.
To make the materials in microgravity one of three methods is employed. One possible method is to use an atmospheric sounding rocket. Another is to use a "drop tower" and yet another method is to use a parabolic aircraft flight, a common astronaut training exercise.
Once a tiny sample of the material has been produced it must then be extensively tested. The project is using the European Synchrotron Radiation Facility (ESRF) in Grenoble, France to scan the new materials. By using the machine's high-energy light (X-rays), it can determine the precise molecular composition and consistency, giving unprecedented insight into why the material works and doesn’t a work, and how Earth-gravity-made material differ from microgravity materials.
Researcher Dr. Reinhart explains the production and testing process, stating, "The aim is to obtain the perfect material that we can compare with the samples we produce on the ground. We investigate them by performing characterization with neutrons and X-rays, in order to get a full description of the materials."
Much of the work is expected to be moved to the Europe's Columbus science laboratory, recently added to the International Space Station (ISS), as its capabilities come online. The space-bound environment will simplify the material production process.
The IMPRESS program is funded by the European Commission's Framework Programme. It features researchers from 40 groups within the EU and Russia.