New aluminium 'foam' for lighter, stronger trains

A new material made of aluminium 'foam' could make future trains much lighter, stronger and safer, German engineers say.
A prototype high-speed train cab, made of aluminium foam, a material better in a crash than fibreglass or regular old metal, was unveiled earlier this year.
A 25-millimetre-thick layer of the 'foam' is sandwiched between two pieces of aluminium, each just two millimetres thick, wired.Com reported.
The foam is actually a low-density, sponge-like composite of magnesium, silicon and copper.
There is no glue, the layers are held together by metallic bonding, the electrostatic attraction of negatively charged electrons and positively charged ions.

The material is 20 per cent lighter than traditional fibreglass, which is commonly used on high-speed train cabs.

Engineers at the Fraunhofer Institute for Machine Tools and Forming Technology and Voith Engineering Services have demonstrated aluminium foam surfaces can be formed economically using embossing tools.
The contours of the material are set during the foaming process, rather than conventionally stretching the material around a blank of the desired shape.
Aluminium foam was invented in 1968, but the longstanding drawback for industrial applications has been the difficulty of shaping the material without relying on expensive tooling.