Do we need to rethink lightweighting? This was one of many interesting questions to come out of the Future Directions for Lightweight Materials and Structures conference organized by the East Midlands Materials Society, the British Composites Society and the Light Metals Division of the Institute of Materials, Minerals and Mining (IOM3), and held at the Space Centre in Leicester, UK.
The need to reduce the weight of components for automotive and aerospace applications – among others – in order to lower fuel consumption has driven much of the research and development carried out by the advanced materials industry over the last two decades or so.
But how significant a benefit have these efforts been in reducing the environmental impacts that these industries have?
During his presentation, Professor of Sustainable Manufacturing at Cranfield University Mark Jolly pointed to a life cycle assessment that shows that the environmental break-even point for an aluminium bumper replacing a steel version that is 4 kg heavier only occurs after the vehicle has travelled 200 000 km, owing to high level of energy embodied in aluminium. Indeed, a car is only driven for 5–7% of its lifecyle.
Current global automotive environmental standards have a tendency to focus on tailpipe emissions.
If a more holistic view was taken, then the case for the use of aluminium and lightweight composites for the production of car parts over heavier but comparatively energy-efficient steel could be significantly weakened.
James Bakewell - Editor, PMNet