MoS2 has a layered structure, the hexagonal crystal system which determines the MoS2 is easy to slide and can play a role in reducing friction.
On the other hand, the ionic bond between the Mo atoms and S atoms giving higher strength MoS2 lubricant film to prevent lubrication film on the metal surface area from being highlighted through. The S atoms in MoS2 exposed on the surface of crystal which can have a very strong adhesion to the metal surface. Chemical properties of MoS2 is stable and resistant to most acids and radiation. Although MoS2 over 400 ℃ in air will produce oxidation, which can affect its lubricity and adhesion to metal surfaces, only when all the lubrication layer is oxidized can Mo coating lose lubrication. The temperature performance of the current MoS2 lubricant far exceeded the temperature limit. The effective temperature range of oil is -60 ~ 350 ℃, while the MoS2 at 1133 × 10-3 ~ 1133 × 10-2Pa under vacuum at 1 000 ℃ can be used and still have satisfactory tribological performance. When there has water in MoS2, its lubricating properties will drop, but can make up electrochemical corrosion caused by another solid lubricant graphite.
