Molybdenum disulfide, also known as mos2 or moly powder, is one of the most widely used solid dry lubricants in industry today. It is often added to oils and greases as an extreme pressure additive to improve their tribological properties, or it can be used by itself as a dry lubricant for high-temperature applications.

MoS2 has a lamellar structure (it is made up of individual atomically thin planes that can slide easily against each other). Like graphite, it is a dry lubricant and does not rely on adsorbed water or vapors for its lubricative properties, although in some cases it has been shown that it does deteriorate under humid conditions.

Unlike graphite, MoS2 is relatively resistant to oxidation and this makes it a natural choice as a solid lubricant for applications in vacuum and in a wide range of temperatures. However, it has been found that the tribological performance of MoS2 can be dramatically degraded under humid conditions, and in such conditions the presence of oxygen leads to a rapid oxidation of the coating [61].

To reduce the effect of humidity on MoS2 coatings, adaptive coatings have been developed that bind carbon nanotubes to the surface of the MoS2 film in a way that increases its mechanical strength and improves its tribological properties. The use of a closed field unbalanced magnetron sputter ion plating process (CFUBMSIP) has been shown to be effective at developing such adaptive coatings. These coatings are now able to operate effectively in a wide range of humid environments and have been successfully used in vacuum and at high temperatures.