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Hot parts:
Protective
coating
for
thrust
E
ver s
ince the first aircraft was built, engineers have
been continually working on improvements and
further developments. The engines in particular –
as the heaviest parts – have the greatest influence on
performance optimization. Not just reduced weight, but
also higher engine working temperatures contribute to
increased efficiency. This is achieved, in amongst other
ways, by using materials which are lighter and more heat
resistant than conventional metals, but introduce a range
of new challenges. And it is precisely here that aviation
developers count on the support of Oerlikon Metco and
its coating solutions.
Fibre-reinforced into the future
Thermal sprayed surfaces ensure efficient engine opera-
tion, protect against corrosion and create a barrier to
heat. This makes it possible to manufacture them us-
ing lighter materials that would otherwise be too delicate.
These materials include, for instance, ceramic matrix
composites (CMC). This fibre-reinforced ceramic is light,
oxidation resistant and also extremely stable at high tem-
peratures. The only weak point of this material: water va-
pour – a ubiquitous product of combustion processes.
This is, however, also no longer a problem with coating,
and the material is already present in the latest genera-
tion of engines.
Layer by layer
Another material with great potential is carbon fibre-
reinforced composite (CFC). Lighter and cheaper than
titanium, it’s the perfect material for the fan blades and
compressor casings of engines.
In some cases, however, CFC needs a wear and abra-
sion resistant coating in order to be able to survive the
harsh environment in which aircraft engines operate. No
easy task, because carbon fibre surfaces are not very
heat resistant, and can thus be damaged by classical
plasma and thermal coating processes. To prevent this,
Oerlikon Metco works with complex intermediate layers
which act as thermal barriers between material and final
coat and thereby protect it against damage. To increase
the efficiency and repeatability of applying these coat-
ings, many customers are turning to Oerlikon Metco’s
cascading arc plasma spray technology.
Faster, lighter, hotter – the biggest challenges that
engine developers face can be thus summarized. To
reach them, aviation engineers rely on Oerlikon
Metco coating solutions.
Efficient coatings for the aerospace industry
by Dieter Sporer