Putting it together – science and technology of composite materials
Box 1 | Composites in Australiaa
Australia, like all advanced countries, is taking a big interest in composite materials, which many people see as 'the materials of the future'. The main concern is to get the costs down, so that composites can be used in products and applications which at present don’t justify the cost. At the same time researchers want to improve the performance of the composites, such as making them more resistant to impact.
One new technique involves 'textile composites'. Instead of the reinforcing fibres being put in place individually, which is slow and costly, they can be knitted or woven together to make a sort of cloth. This can even be three-dimensional rather than flat. The spaces between and around the textile fibres are then filled with the matrix material (such as a resin) to make the product.
This process can quite easily be done by machines rather than by hand, making it faster and cheaper. Connecting all the fibres together also means that the composite is less likely to be damaged when struck.
With the costs coming down, other uses for composites are beginning to look attractive. Making the hulls and superstructures of boats from composites takes advantage of their resistance to corrosion. The Australian Navy’s new minehunters have composite hulls, since the magnetic effect of a steel hull would interfere with mine detection.
Also in the pipeline are carriages for trains, trams and other 'people movers', made from composites rather than steel or aluminium. Here the appeal is the lightness of the composites, as the vehicles then use less energy. And we are going to see more and more composites in cars for the same reason.
Related site
Cooperative Research Centre for Advanced Composite Structures Ltd (Australia)
Posted November 2000.