Dry Film Lubricants:
Dry film lubricants, also known as solid film
lubricants, provide a lubricating film that
reduces friction, inhibits galling and seizing
and in some instances can aid in dispersing
heat. They are slippery and provide an extremely
low coefficient of friction.
One of the obvious reasons for
using a lubricating coating is to reduce friction,
which improves wear, extends part life and frees
up H.P. normally lost to friction. A second
major benefit is a reduction in part temperature.
This is especially important to such parts as
valve springs.
Thermal Barrier Coatings:
Thermal Barrier Coatings (TBCs) are designed
to reduce the movement of heat. In some instances,
such as exhaust systems, you want to keep the
heat within the part. In combustion chambers
you want to use the heat generated by combustion
to push down on the piston rather than bleed
off into surrounding surfaces. Due to continued
testing we are learning that simple thermal
barrier action is not the only characteristic
that is important. In fact certain TBCs
will move an engine into detonation. TBC coatings
can be made from a variety of materials. Ceramics
get the most attention, though there are other
materials that are superior in specific applications.
The proper choice is critical to the overall
function of the coating.
Thermal Dispersants
Being able to move and control heat is of tremendous
importance. Excessive temperature can lead to
metal fatigue, boiling fluids, damaging metal
expansion, reduce electrical efficiency and
a host of other problems. Traditionally dealing
with heat has been handled either by expanding
the radiating surface, constructing parts from
materials that are more heat conductive and
using the color black.