Abstract
The friction characteristics of unbonded molybdenum disulphide surface layers have been studied as a function of ambient humidity, specimen temperature, speed and load. Measurements have been made of static as well as kinetic friction in order to distinguish the influence of frictional heating. The static friction coefficient increases with increasing humidity; this effect is much more pronounced at low specimen temperatures. For given specimens the static friction is a unique function of the relative humidity at the bearing interface. The results provide evidence that the process governing the changes in static friction is one of physical adsorption of water. A similar effect governs the kinetic friction; in this case the adsorbed water is partially desorbed by the friction heating and this results in a marked decrease in friction coefficient. This effect also explains the “transient” high friction coefficients reported previously. These occur at the beginning of sliding in humid air before frictional heating has any effect. No transients are found in dry-air conditions. The friction decreases with increase of load independently of the effect of frictional heating or of humidity. High humidity is also found to increase the wear rate of the unbonded lubricant layer.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
