Formulating The Light Fantastic
The Age
Monday May 21, 2007
Researchers at Deakin University are at the forefront in developing lightweight materials for planes and cars. Geoff Maslen reports.
BRONWYN FOX was in the US last week when a senior executive of the world's largest manufacturer of aeroplane parts confided a truth she had already grasped. "The day of the aluminium plane is over," said the man from Spirit AeroSystems. As head of a team of eight doctoral research students at Deakin University, Dr Fox sees a time in the not-too-distant future when not only planes but cars will be built from carbon-fibre composites - machines that weigh less, are more fuel-efficient and safer."There are enormous benefits in converting steel and aluminium parts in cars to lighter materials, especially in fuel savings," she says. "Using carbon-fibre composites produces lighter cars; lighter cars are more fuel-efficient; carbon fibre has a higher stiffness-to-weight ratio than steel but it also absorbs more energy per kilogram and has the potential to make cars lighter and safer."Dr Fox says that as well as making aeroplanes lighter and more fuel-efficient, the melding process she and her team are investigating also works to make them safer. The fewer joints and rivets there are, the fewer points for fractures to occur.A senior lecturer in Deakin's centre for material and fibre innovation, she is leading research into developing a new and faster process for producing carbon-fibre composites. While the idea sounds novel, humans have been using composite materials for thousands of years.From wood and mudbricks to concrete and fibreglass, the composites usually consist of just two materials. One, called the matrix, binds together a cluster of fibres of a much stronger material, the reinforcement, so they work together to give the composite unique properties.After graduating in chemistry from the University of Melbourne, Dr Fox worked at the CSIRO for four years before undertaking her PhD at the Australian National University and then moving to Deakin, where she became leader of the composite research team.The research is supported by the Victorian Centre for Advanced Materials Manufacturing and Quickstep, a Western Australian company. Quickstep has developed a process that enables carbon-fibre composites to be hardened or "cured" much faster than placing them in an autoclave or very hot oven."Instead of using gas to fire an oven, we use a fluid called polyethylene glycol that can be heated much faster. We pump the fluid into two giant bladders and the composite material to be cured is placed between them like a toasted sandwich maker," Dr Fox says."This is the world's first computer-controlled plant and our research is exploring the boundaries of where it can be useful, finding applications - while uncovering some fundamental science as well."The researchers have discovered that improving the adhesion of the fibre to the matrix is the key to improving the strength of the composite material. They are collaborating with aerospace companies in the US and Germany to demonstrate how this can be used in manufacturing aircraft parts."We've developed the technology to make composite tubing, which is great for crash structures in the automotive industry, as well as low-corrosion piping that we've jointly patented with Quickstep," Dr Fox says.But the crucial factor will be showing how the Quickstep process can be used to speed up the manufacture of a new class of plane. Current plans in the US are aimed at phasing out the aluminium-based 737 planes and replacing them with others largely made from carbon-fibre composites.Dr Fox says curing the parts in a conventional autoclave can take up to 20 hours, which would hold back plans by the plane manufacturers to make 40 of the new aircraft every month.Similarly, the Boeing company wants to produce eight of its new 787 Dreamliner planes every four weeks. The wide-body, twin-engine jet liner will be the first major plane to use composite material for most of its construction - a move that will slash its weight by thousands of kilograms.Even before it reaches the runway, the 787 has become the fastest-selling wide-bodied airliner while still at the construction stage. Fifty per cent of the material used in the construction is composite, 20 per cent aluminium, 5 per cent titanium, and 10 per cent steel.Because the 787 will be a very light aircraft for its capabilities, it will have the potential to take off from, and land on, relatively short airstrips, as the 767 can, yet still be able to fly long distances. The 787 production line will be able to finish an aircraft in as little as three days compared with 11 days for the 737, Dr Fox says.So how did a chemistry graduate not only end up completing a PhD in a branch of engineering but also work with a team of fellow engineers of whom half are women?"I wanted to study engineering but I thought it was all about building bridges," Dr Fox says. "If I'd known 15 years ago what careers there were I'd have done it straight away."My ideas changed at the CSIRO, where I could see the engineers were having all the fun - they got to make things and break them - and I decided that's what I wanted to do."Material science offers great opportunities for teamwork and creativity - and great career opportunities for women who enjoy doing those sorts of things."
© 2007 The Age
