Aluminum foam for light, strong trains

London: German engineers have made a new material which could make future trains much lighter, stronger and even safer. Two layers of aluminum hold metal alloy ‘foam’ made of magnesium, silicon, and copper and aluminum and the material is stronger than fibreglass or even just metal, Wired reported.

The 2 mm thick layers of aluminium hold 25 mm of ‘foam’ together without any glue, just by electrostatic attraction (negatively charged particles bond onto positively charged ions). Even when no adhesive is used, the bonds are so strong that when pulled apart, it destroys the foam rather than slip away.

"Aluminum foam has a very high and comfortable impact resistance, especially for small impacts like stones, bottles or just birds," Ralf Uhlig of Voith Engineering Services, which was involved in the construction of the prototype, was quoted as saying.

Aluminum foam was invented in 1968 but the difficulty of shaping the material without expensive tooling, hindered its applications. Engineers at Fraunhofer Institute and Voith Engineering Services made the aluminum foam surfaces economically.

"We save approximately 60 per cent on tool costs," explained Thomas Hipke, from Fraunhofer Institute Hipke. Train bogies assembled from aluminum foam are expected to be built in 2015.