What is Molybdenum Disulfide and why is it showing a good lubricating behavior?
Molybdenum Disulfide, also known as Molybdenum Disulphide, MoS2 and Moly, is one of the most widely used solid film lubricants. Like graphite and tungsten disulfide (WS2), MoS2 is a dichalcogenide. The lubricating properties of molybdenum disulfide lubricant are due to a weak atomic interaction (Van der Waals Force) of the sulfide anions, while the covalent bond within the molybdenum is strong.
Which are the easiest and widely recognized ways of applying MoS2 coating?
There are a number of ways to apply MoS2 low friction coatings to the desired substrate. These include:
- Rubbing and burnishing
- Impingement with or without inorganic binder
- Spraying or dipping paint like substance containing the molybdenum disulfide as a lubricant
- Physical vapor deposition
Some of the specifications covering this application are; MIL-PRF-46010, AS5272, AMS2526.
Why molybdenum disulfide coating is considered unbeatable in comparison to its competitors?
In moving/mating components, friction causes considerable loss of energy, poorer performance, and limits the wear life of the components. Molybdenum Disulfide can provide a low coefficient of friction, sometimes as low as 0.05 COF. This will be dependent on the humidity, cleanliness, and sliding conditions of your application.
Also, the molybdenum disulfide dry lubricant can:
- Operate in a wide range of temperatures up to 600 deg F and maintain its lubricity in high load, high speed conditions.
- Be very effective in inhibiting corrosion as well when combined with the proper resins and binders.
Lubrication relies on the slippage along the sulfur atoms. All of the properties of the lamella structure are intrinsic and no external form of moisture is required (as it is with graphite). Mos2 performs best when water vapor is not present, making molybdenum disulfide coating ideal for vacuum applications.
|Coefficient of Friction||0.06 to 0.15|
|Substrates||All ferrous or non-ferrous metal
Man-made solids & plastics
|Cure Time||No cure time is required when applied at ambient temperature|
|Applications||Chucks, Collets and Tools
Circuit Breakers and Switches
Compressors and Rheostats
Engine and Drive Train Parts
High Vacuum Applications
Machine tools, Pins, Taps
Pilot Valves, Chain Saws
Rubber Gaskets, “O” Ring Seals
|Relative Load Carrying||250,000 PSI|
|Ambient Temperature Range||-185 to 350 ºC|
|Vacuum Temperature Range||-185 to 1100°C at 10-14 Torr|
|Chemical Stability||Inert, non-toxic, corrosion resistant|
|Hardness||1.0 on Mohs Test|
|Electrical Properties||Has semiconductor properties|