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Surface improvement is of more concern in today’s industrial environment. The
enhanced demand for higher efficiency and more productivity increases the need for
more reliable and high performance components. In most of the cases, the rapid
wear and eventual failure of the components subjected to damage of material are due
to the environmental conditions and also high relative motion between the mating
surfaces which causes cyclic stresses and high temperatures.
To avoid these types of results, a protective coating layer has been introduced to
the surface of the component which acts as a barrier between the component and the
aggressive environment. This method is very advantageous and is being accepted
universally by the manufacturing and engineering industries. Coatings historically
provide a protection against erosion and corrosion of parts, and protect the material
from chemical and physical interaction with its inside and outside environment
(Fauchais and Vardelle, 2012). Solid particle erosion is a dynamic process that leads
to progressive loss of material from the target surface due to impingement of fast
moving solid particles (Demasi, 1994). During flight, a particle carries momentum
and kinetic energy, which is dissipated during impact at target surface (Oka, 1990).
The function of abradable coatings is to not only allow sharp clearances but also
automatically adjust clearances, i.e., to accept physical harm and thermal changes
that may be found in devices. In aircraft jet engines, abradable coatings are used in
the compressor and turbine sections where a minimum clearance is required between
the blade tips and the casing.
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