An investigation of friction and wear performances of bonded molybdenum disulfide solid film lubricants in fretting conditions

The friction and wear performances of bonded MoS2 solid film lubricants with the counterpart steel ball rubbing were investigated in fretting wear conditions in order to inquire into the load-carrying capacity and wear mechanisms of bonded MoS2 solid film lubricants under dry friction conditions. Experimental results show that the bonded MoS2 solid film lubricants have excellent anti-friction and wear-resistance performances within a wide load range between 20 N and 800 N and within a wide oscillatory frequency range between 5 Hz and 30 Hz. It is found through analyses of the transfer films formed in the surface of the counterpart steel ball investigated by SEM, XPS and AES, that the thickness of the transfer film formed is about 38 nm and the oxidation of MoS2 in the transfer films does not occur during dry friction process. The high load and frequency promote the formation of a compact transfer films. The compact transfer films are believed to be the predominant mechanism giving rise to high load-carrying capacity, and excellent wear-resistance performances of the bonded MoS2 solid film lubricants.