Engineers preparing to launch metallurgy projects aboard the International Space Station.

Metalcasting will soon expand its role in space travel thanks to investigations conducted at the University College Dublin (UCD), Ireland, as reported in the Irish Times, Dublin. With assistance of research partners from several countries, the Irish engineers are working on two programs, CETSOL and IMPRESS, which are designed to improve the understanding of gravity's effect on metalcasting and solidification. Once set in place, the studies will be performed inside the International Space Station (ISS).

CETSOL investigates how micro-gravity affects conventional metalcasting, particularly aluminium. Organized and funded by the European Space Agency (ESA), UCD is working on computational modeling of how molten alloys crystalize and solidify.

Computer models will describe how crystal growth occurs in the solidifying casting, and predictions from these models will be used to design and build experiments for the space station.

IMPRESS is also coordinated by ESA but funded through the Sixth Framework Program for European Research. In this program, UCD is involved in two areas, computational modeling of the behavior of specialist alloys and the design of experiments for the ISS. IMPRESS focuses on exotic materials known as "intermetallics," which are like metals but have a different crystal structure and are harder, tougher and more temperature-resistant than conventional metals. The engineers plan to use the micro-gravity available in space as a way to isolate the effects of natural convection by comparing castings made on earth with those aboard the ISS.

"On board the space station, the conditions are those of freefall, the centrifugal force is exactly equal and opposite to the gravity force. There is no net gravity," said David Browne of UCD's Dept. of Mechanical Engineering.

He noted that the lack of gravity would make for a "unique environment" on how alloys solidify in a mold because there is no steady flow of liquid. Thus, the typical microstructures of components cast on earth could be much different aboard the ISS.

The studies will focus on titanium aluminide for use in turbine blades and nickel aluminide for use as catalysts. "It is related to the development of industrial processes, which can successfully produce useful components from these intermetallic materials," said Browne.