Design Engineering
Basic
Meeting Your Toughest Performance Specifications
As the jet age dawned, the standard liquid lubricant available couldn’t meet the higher demands of advancing technology. Everlube Products got its start by developing solid film lubricants to meet the rigorous demands. Solid film lubricants improve performance in a variety of situations: corrosion, wear, friction, release, lubrication, extreme temperatures and in many other adverse operating conditions.
Identifying engineering problems and developing coating solutions is what we do best. We apply the same type of creative thinking to develop engineering coatings to meet your toughest performance specifications.
What are solid film lubricants/coatings?
The category solid film coatings includes the traditional solid film lubricant products. The solid film coating definition is broader due to the wide range of performance improvements available.
Solid film coatings/lubricants are materials with inherent lubricating properties, which are firmly bonded to the surface of a substrate by some method. Common methods of bonding are resin deposition, burnishing, mechanical impingement, sputtering, ion deposition, or physical vapor deposition. Of these, resin bonding has the most commercial significance.
The formulation of resin bonded solid film coatings/lubricants can be a very complex process. There are three major areas which have to be addressed. The first is the lubricant base material (pigment) selection. The second is resin or binder selection, and the third is any other materials that may be needed to augment the properties of the coating.
Each coating has different base material (pigment) properties. MoS2 in combination with graphite results in superior lubrication. MoS2 alone offers better corrosion resistance. Graphite alone, although rarely used in this condition, results in better conductivity and functions better under radiation.
How do they work?
After application, the carrier evaporates. As the resin cures either by air drying or oven curing, it binds the solid coating lubricant particles to the surface of the part. These lubricating particles prevent surface-to-surface contact, thus reducing friction and wear between mating surfaces.
Why use a solid film coating lubricant?
Bonded solid film coating lubricants were invented over 40 years ago to meet the unique problems of the then emerging aerospace industry. They can be used where conventional wet lubricants are ineffective or can’t be re-applied. They offer advantages other lubricants don’t, including:
- Effective lubrication over a wide temperature range – from 395°F (201°C) to over 2000° F (1093° C) – where greases and oils are ineffective.
- Some withstand loads in excess of 250,000 psi ( 1,666,666 kPa), and typically exhibit a lower coefficient of friction as load increases.
- Unique resistance to corrosion and chemicals.
- In dusty, dirty environments they don’t attract or hold contaminants.
- Some are formulated to withstand such extremes as radiation, a hard vacuum and liquid oxygen.
- No maintenance required.
- Perfect for parts not accessible for relubrication.
- Ideal for use on equipment operated intermittently, because solid film coatings don’t deteriorate or migrate over time
What are situations where solid film coating lubricants are used?
- On parts that come in contact with harsh contaminants such as chemicals, fuels, and solvents.
- Where adjacent parts could become contaminated by migration of liquid lubricants.
- On heavily loaded equipment susceptible to galling and seizing, particularly aluminum, stainless steel and titanium.
- Where two dissimilar metals are in contact to prevent galvanic corrosion
- Where dust or other airborne debris could become entrapped in wet lubricants and impair machine operation.
- Where operating temperatures exceed the range of oils and greases.
- Where fretting corrosion is a problem.
- Most moving parts…. fasteners, gears, cams, ball joints, bearings, slides, valves, levelers, rollers, conveyors. The possibilities are virtually unlimited.
How are Solid film coating lubricants applied?
They can be applied by spraying, dipping, brushing, spray/tumbling or dip/tumbling. Most solid film coating lubricants achieve optimum wear properties when applied to a total thickness between 0.0003 inch (.00007 cm) and 0.0007 inch (.00017 cm), and when the lubricant is applied in very thin, multiple, uniform coats.
Solid film coating lubricants should be viewed as a system, taking into account the base material, the surface pretreatment, the method of application and the correct cure cycle. Eighty percent of all solid film coating failures are due to incorrect surface pretreatment and application; the rest are generally because the appropriate coating lubricant was not selected.
One of the most critical aspects of application is to employ the right pretreatment method and to employ it properly. Over the years, various pretreatment methods have been identified for solid film lubricants on a wide variety of metallic substrates. These pretreatment methods are described below:
Recommended Pretreatments for Various Substrates