It
should be noted that some coatings will fall into more than
one category. You might have, as an example, a Corrosion
Inhibitor that is also a Thermal Dispersant. The following
information will provide a general overview on coatings
falling into these categories.
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. The appearance is generally a charcoal gray and takes
on a sheen upon burnishing. They are slippery and provide
an extremely low coefficient of friction.
The
two most important components are the binders and lubricating
ingredients. Without a good binder the coating will not
stay in place and will simply cold flow or buff off in operation.
Similar coatings using the same pigments but different binding
systems can show a wide variation in load carrying abilities,
ranging from 100,000 psi to over 350,000 psi . The pigments
determine the actual lubricating potential. PTFE, as an
example, is listed as having the lowest coefficient of friction
(COE). However, under high speed and load, the COE of PTFE
degrades while that of MOS2 (Moly) improves, until it is
significantly better than PTFE. Selecting the proper ingredients
can make or break a coating.
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. Here the pigment
choice is critical as certain ingredients can trap heat
in a part. Not all coatings are created equal. . It is recommended
that coatings using PTFE be avoided in these cases. Contact
us before choosing a dry film lubricant.
Thermal
Barrier Coatings
Thermal
Barrier Coatings (TBC’s) 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 TBC’s 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. With advances
in thermal management methods additional ways of enhancing
heat transfer now exist. Our supplier, TECH LINE has developed
a Thermal Management System™ . Individual products
such as TLTD can be utilized by themselves or in conjunction
with other coatings to manage the flow of heat. TLTD is
capable of transferring heat faster than the bare metal
surface. While TLTD does make use of the color black, TLTD
is more than a simple "black body" heat emitting
coating. TLTD includes ingredients that also contribute
to increased heat flow. Combining these properties with
increased corrosion protection and the thin film application
technique, maximizes thermal transfer capabilities. Effective
on Brakes, Intake Manifolds, Cylinder Heads, Oil Pans, Radiators,
Intercoolers and more.
Certain
Dry Film Lubricants we apply are capable of reducing part
temperature not only through the reduction of friction but
also through increased thermal flow. The active ingredients
accelerate the movement of heat. This is especially beneficial
on valve springs where excess heat can lead to accelerated
fatigue and in some instance breakage.
Corrosion
and Chemical Inhibiting Coatings
The
loss of effectiveness, reduction in part life and deteriorating
appearance due to corrosion/chemical damage is of real concern.
Loosing a well matched/tuned header to rust is not only
expensive, but frustrating. A good aluminum manifold can
become junk if the water inlet area corrodes excessively.
Keeping components clean and attractive is of concern when
promoting your vehicle or the parts you manufacture to potential
sponsors or customers. We offer a variety of protective
coatings that also enhance the appearance of a part. Many
of these coatings will have additional benefits such as
Thermal Barrier or Thermal Dispersants capabilities. |
