primary objective of any European institution must be to protect Europe
and its interests and that includes the environment. In the case of
air pollution, numerous initiatives have sought to limit and regulate
industrial emissions, but much of the air pollution seen in our cities
is caused not by factories but by automobiles. A European research
project has developed revolutionary lightweight automobile parts,
including a hollow camshaft and new aluminium brake disks. The new
elements have laser-hardened surfaces, making them as strong as or
stronger than conventional cast-iron parts, and their reduced weight
means lower fuel consumption and emissions. Partners believe the potential
market for light automobile parts is enormous. European SMEs in the
metal-coating and machining sectors can carry out the laser-hardening
Much of the fuel consumed by the ever-increasing
number of cars, buses and lorries on our roads goes to moving the
vehicles themselves and not the people and goods inside them. Lighter
engines, chassis and other parts would mean a reduction in fuel
consumption, but many of these components must be extremely hard
and solid, making the use of lighter materials unfeasible or even
Breaking new ground
The idea behind the project started at Adam
Opel in Germany, where designers were looking for ways to reduce
weight in automobile components. The limiting factors of lightweight
materials include hardness and strength. But new coating technologies
do exist for rendering surfaces harder than the underlying substrate.
With a sufficiently hard surface, automobile parts might not need
to be solid throughout.
With these considerations in mind, partners set out to design and
produce a revolutionary hollow camshaft for automobile engines using
rotary swaging, a technique whereby cold metal is pressure-formed
into shape. The new camshaft is 50% lighter than conventional cast-iron
camshafts, representing an equivalent saving in steel. Its surfaces
are hardened using a completely new process involving spray application
of a carbon coating which is then melted on with a laser beam. Processing
time for a single cam is approximately 75 seconds for carbon spraying
and 30 seconds for the laser treatment. The laser hardening process
is extremely interesting for camshafts as conventional hardening
techniques can result in significant distortions.
Then, new laser-hardened aluminium brake-disks were developed, 30
to 40% lighter than the conventional cast-iron disks. The extreme
hardness, durability and lightness which have been achieved in these
new components is no less than revolutionary.
Finally, one additional application was added in the machining sector.
Techniques for applying high molybdenum-content layers to industrial
extruder screws were developed, providing 60% better wear performance
compared to similar plasma transferred arc (PTA) layers currently
Partners included seven German and Spanish companies.
The impetus came from Adam Opel AG, in Germany, but other German
groups contributed expertise in advanced rotary swaging techniques
and glue spraying of carbon layers. The Fraunhofer Institut für
Lasertechnik specialises in laser surface treatments and also provided
project co-ordination. Spanish partners provided expertise in laser
treatment and plasma spraying, and introduced the concept of a lightweight
aluminium brake disk.
According to estimates, 180 million automobiles could be fitted
out with hollow camshafts in Europe alone within just a few years
of project completion, a market representing up to 80 million euro.
A weight reduction of 50% or 3 kg for a 4-valve, 6-cylinder engine
would mean a reduction in fuel consumption of 0.11itres/100 km.
Total fuel savings for 90 million cars would reach 108 million euro/year.
Furthermore, laser-beam treatments can be carried out by European
SMEs in the metal-coating and machining sectors.
Interest in the new production techniques
is very high within the laser beam surface treatment and laser-related
gas technologies industries for applications in a variety of industrial
sectors. Further research and development efforts are necessary
to improve quality. Schwäbische Hüttenwerke GmbH, another
German partner, has installed a new high-pressure rotary swaging
machine and is now developing a revised hollow camshaft based on
the results of this project. Krauss Maffei Dienstleistung GmbH in
Germany is following up on the work with extruder screw coatings
and is applying the developed alloy to their screws. Partners cite
the combination of technical expertise and concrete market interest
as being instrumental in the project's success.