Friction Characteristics of Molybdenum Disulfide Thin Films Synthesized via Plasma Sulfurization

Herein, the tribological behavior of layered few nanometer‐thick MoS2 thin films is evaluated to identify their applicability to an oil‐free solid‐lubrication coating layer. The MoS2 thin films are synthesized using a plasma sulfurization process with optimized steps and conditions derived from a previous study. MoS2 thin films with different thicknesses are heat treated at 400 °C to investigate the effect on their tribological properties. The ball‐on‐disk method is used to observe the friction and wear behavior of the MoS2 thin films, and this test is carried out under an applied load of 0.5 N in an ambient atmosphere (≈23 °C). The coefficient of friction of the unheated MoS2 layers increases rapidly at 32–36 cycles regardless of the thickness. However, the heat‐treated MoS2 films maintain a lower coefficient of friction for more cycles (60–86 cycles). The heat treatment effect effectively increases the wear life of the MoS2 thin film. Based on this result, it is believed that the heat‐treated MoS2 thin films can be potential solid lubricant candidate for micro‐ and nanoelectromechanical systems.