Photo: International Space Station courtesy of the European Space Agency
IMPRESS (Intermetallic Materials Processing in Relation to Earth and Space Solidification) is a pan-European integrated project involving 42 leading research groups in metallurgy, chemistry, computer modelling, environmental engineering and industrial product development.
The five-year project, begun in late 2004 and due for completion in 2009, brings together research partners from 15 European countries, including three new member states and Russia, under the coordination of the European Space Agency.
A team based in the UCD School of Electrical, Electronic & Mechanical Engineering is playing a key part in this European-wide project that will push the boundaries of what metals can be expected to do. What is their part in the enterprise? Designing a furnace that can test new alloys at temperatures of up to 1500 degrees C. Actually, that’s the easy part. The difficult bit is that the furnace is operated in space, in the laboratory of the International Space Station, to be precise.
Dr David Browne leads the UCD input into the project. He supervises the work of two research fellows, Dr Marek Rebow and Dr Mingming Tong. It’s the group’s second involvement with the European Space Agency.
The project aims to produce metal alloys which will withstand the pressures and temperatures of turbine engines – but which will be lighter and stronger than the existing components.
“The blades of the turbines reach temperatures of over 600 degrees Celsius,” explains Dr Browne. “Obviously if they soften in an airline engine, the plane is in trouble. So what we’re trying to do is to make them lighter but still strong at high temperatures.”
Lighter metals used in airline engine turbines have obvious benefits. They increase fuel efficiency, extend flights, and may lengthen the lifespan of the engine. Dr Browne also suggests that the technology would have applications in turbines used in power generators and in industrial gas turbines.
Dr Browne inside a model of Columbus -
the European Microgravity Lab
It’s this immediately practical application of the technology that has persuaded industry leaders such as Rolls Royce to join the IMPRESS project. Explains Dr David Jarvis, the project co-ordinator: “One of the most sensible ways is to develop more efficient, cleaner technologies. Turbine blades made from titanium aluminide will be used for aero engines and gas turbines, because they are 50 per cent lighter than current nickel superalloys. That gives them a huge competitive edge. Also by reducing the weight of the blades, it’s possible to increase the thrust/weight ratio of the turbine, which means far better fuel economy and reduced exhaust pollution.”
Why do it in space? Experiments done at zero gravity enable researchers draw a better picture of the metal’s properties. “Obviously we don’t want to build a factory in space,” says Dr Daniella Voss of the IMPRESS project management team in the Netherlands. “But we want to understand more fully the properties of the metals. We can then build better computer models of the processing of these new materials.
This entails, says Dr Browne, heating the special metal alloys, called intermetallics, to temperatures of up to 1500 degrees C and then re-solidifying them, while their performance is monitored. This will be done in the furnace designed in University College Dublin.
“On earth, gravity makes it hard to measure some properties – as it masks some properties. In space – at micro-gravity – you can measure some things without the effect of gravity-driven flow in the liquid metal,” says Voss.
“When in space,” continues Browne, “the astronauts push the buttons and following the instructions of the research teams. We’ve got to consider what experiments are to be carried out, but we’ve also got to make sure they’re user-friendly for the astronauts who can’t be expected to be experts in every discipline. Also, we’ve got to make sure it’s safe – the astronauts can’t just jump out if something goes wrong.”
The experiments in space, however, are not the only micro-gravity opportunities. IMPRESS also conducts experiments on specially commissioned airliners that can attain micro-gravity conditions by describing an arc in flight – so-called parabolic flights. However, such flights offer only about 20 seconds of micro-gravity. The teams will use sounding rockets - unmanned rockets that attain micro-gravity conditions on board for 6-12 minutes during free fall.
The UCD team is also involved in designing computer models for a further set of experiments on fuel cell catalyst powders, some of which are conducted in space. Hopes are high for the short-term practical gains that the series of experiments offers. According to the EU Commission, which is funding the project, IMPRESS input to turbine and fuel cell technologies promises Europe a leading position in both areas, where world demand is estimated at €45 billion by 2011. IMPRESS also has the potential to make a major contribution to meeting the reduction of CO2 and NO2 emissions under the Kyoto Protocol. “What we’re trying to do with the IMPRESS project,” says Voss, “is invent a new way of doing things.”
- For more information on IMPRESS visit http://spaceflight.esa.int/impress/