Molybdenum disulfide (MoS2) dry film lubricant (AKA “moly”) is a solid film lubricant used by many aerospace, nuclear and military manufacturers for the lubrication of small mechanisms. It’s effective at extreme temperatures and pressures, resistant to oxidation and complies with all of the necessary industry standards for lubricants to be used in nuclear reactor applications.

When MoS2 is applied, it forms a bonded film on the substrate that reduces friction and wear, and prevents seizure and galling. It’s most often sprayed or dipped on to the substrate for application, but it can also be applied by physical vapor deposition, impingement with or without a binder, and by rubbing or burnishing.

Although bonded MoS2 has excellent tribological properties, it has only limited application due to its relatively low limiting PV values in vacuum and atmospheric conditions. Furthermore, it can exhibit high levels of friction and wear when humidity is present in the tribological interfaces. The lubrication performance of MoS2 can be greatly improved when the pretreatment of the substrate is considered. In particular, the surface texture of the substrate is important as it anchors the bonded film and influences its tribological behavior.