For closed-cell aluminum foam, a nanotech-based process control step brings performance advantages. Automakers are testing.
Worried that rising fuel costs will shrink the object of your automotive love affair? Lighten up because that's literally what carmakers may be doing with a new nanotechnology-enabled weight-reduction strategy. With the nano refinements in the process-control step, closed-cell aluminum foam gains advantages for structural applications. For example, tests by BMW demonstrate how the nanostructure-controlled process is reinventing foamed aluminum. "Our research is leading to five patents," says Gerald Hoegl, CEO, Metcomb Nanostructures, the Kleinreichenbach, Austria, innovator.
The key innovation, Hoegl explains, is how nanotechnology controls and maintains the size of the closed cells comprising the foam. He says a primary benefit of the nanotech-controlled process is the virtual elimination of unwanted closed-cell size variations during a production run. Next year, when Metcomb commercializes parts production, customers will be able to specify cell diameters anywhere within a 5-mm to 15-mm range, adds Dietmar Leitlmeier, Metcomb's chief technical officer. Cell-wall thickness also can be selected and maintained, he adds. The potential exists for closed-cell aluminum parts to replace heavier metals in automotive, aerospace, defense and construction applications, says Leitlmeier. He says the energy-absorbing capability of the material also offers potential for armor and blast containment.
In the BMW tests with engine mounts, weight savings of 30% were shown to be possible. In addition, the parts demonstrated enhanced capability, including better sound and vibration damping plus greater stiffness.
Metcomb's foam is approximately 70% to 85% lighter than solid aluminum. Metcomb says typical parts would have a dense aluminum skin.
In addition to the engine- mount demonstration, doors also were tested with one configuration revealing a 7-pound savings per door. Metcomb says automotive potential also exists for such things as crash absorbers, door side beams, knee bolsters, gear box cross members, sill reinforcement parts and "A" and "B" pillar reinforcement parts.