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. Selecting the proper ingredients can make or break a coating.
One of the obvious reasons for using a solid or dry film lubrication coating is to reduce friction. A simple reduction in friction greatly reduces component interface contact wear, which in turn, frees up horsepower typically lost to friction.Polytetrafluoroethylene (generically known as teflon) has the lowest coefficient of friction of any known solid. For this single reason engineers for years have experimented using polymers as a solid lubricant on engine components in an effort to reduce friction. Again, because of the low coefficient of friction, PTFE (or polymer) powders are added to engine lubricants to reduce friction and wear between mating components. However, PTFE is extremely soft and expensive. Fluorocarbons are various chemically inert compounds containing both carbon and fluorine and are used mainly in lubricants and in the making of resins and plastics. Fluorocarbons are hard. When blending fluorocarbons with fine PTFE particles along with selected fillers, binders, and pigments you have a complex matrix formulation known as a fluoropolymer. A properly formulated dry film coating offers the known friction reducing characteristic of PTFE and fluorocarbons in conjunction with the wear characteristics of the specifically selected bindersand fillers.
There are obvious critical areas associated with power loss and damage caused by inadequate lubrication. Two of the highest frictional contact surfaces in an internal combustion engine are design situated between the piston skirts and cylinder walls, and the interfacing contact area of the crankshaft journals and corresponding rod and main bearings. When introducing high velocity reciprocating movement, one can only hope that hydrodynamic (boundary) lubrication is occurring. Wait a minute, how about "cold starts" when all the oil has drained down off the piston skirts and departed the bearing surfaces…isn't the engine literally operating dry! Reason enough for having components dry film coated. However, don't ignore the Performance Enhancement benefits of dry film coatings designed to significantly diminish friction and freeing up wasted energy (horsepower)..
Gear type oil pumps (wet sumps) require extremely close internal tolerances to properly scavenge reserve oil from the pan and then force it through the engine's oiling network. Consequently, during operation there is substantial friction taking place which is consuming an enormous amount of energy and is converting this energy into unwanted heat. Once again we have a "horsepower" thief that can be eliminated. Dry-Film Coating is a moly-based lubricant capable of providing lubrication at levels as high as 350,000 psi. The lubrication aids in preventing scuffing and galling, increasing part life. It also reduces friction, freeing more useable power. This lubricant provides extra protection by preventing damage from oil film failure. Dry-Film Coating is actually impregnated into the metal surface so no dimensional changes are realized. In addition to lubrication, Dry Film Lubricants also help distribute heat so less metal fatigue is caused reducing the chance of part failure.