The applications of thermal spray-coating are numerous and
widespread – from non-stick pans and irons, via engine parts
and turbine blades to medical implants. The coatings serve
primarily to protect the underlying surfaces from mechanical and
thermal load, or chemical attack. Staff at the Empa Thun have made
an internationally recognized contribution to the success of this
new technology with their work over the past eleven years in the
sole Swiss institution developing materials and coatings, and
conducting scientific research in the field of thermal
spraying.
Some of the newest research results were on show in Basel, for
example nanopowders which serve as the raw materials for several
processes involving thermal spray-coating. The powders consist of
particles with diameters below 100 nanometers, and when compared to
the original materials from which they are made they have new and
startlingly different properties. With its two newly completed
pilot plants, the Empa is now able to produce tailor made
nanopowders at a rate of kilograms per hour.
Another current Empa development is a continuously porous and yet
extremely strong titanium coating for hip replacement implants.
This novel surface allows significantly better binding between the
patients’ bone and the implant, because the coating consists
of connected pores throughout its thickness. The bone cells can
thus grow though the entire depth of the surface.
In addition to these developments, the Empa also demonstrated a new
method of measuring the adhesion of deposited layers, a cooperative
project involving other European research institutes and supported
by Swiss industrial partners. The new technique permits researchers
to measure cohesive or adhesive failure of a surface layer –
that is to say fractures within the coating, or separation of the
coating from the substrate at the boundary surface. An instrument
which operates using the new technique is already commercially
available, and its use is expected to lead to a proposal for
establishing a new European and international standard.
Over the three days, the ITSC offered a wealth of state of the art
information. The conference program included 229 lectures, 90
posters and an exhibition with over 30 stands presenting
internationally leading companies. In addition, an industry forum
was used to demonstrate practical applications and introduce
selected firms. The conference was organized by the American
Society of Materials – Thermal Spray Society (ASM-TSS), the
International Institute of Welding (IIW) and the German Association
for Welding and Related Techniques (DVS).
Author: Dr. Bärbel
Zierl
Contact:
Dr. Stephan
Siegmann, Head, Empa Coatings Laboratory, Tel. 033 228 29 45,
stephan.siegmann@empa.ch
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