Chemical and Structural Effects on the Lubrication Properties of Sputtered MoS₂Films

Quantification of a lubricant transfer process that enhances the sliding life of a MoS2 coating

“…Fusaro has also documented similar retransfer processes for MoS 2 [13] and other solid lubricants [14]. Fleischauer et al [4] and Singer et al [5] have shown that early loss of lubricant from tracks correlates with buildup of transfer film on the counterface, and Lancaster [15] has argued that transfer films play a crucial role in the endurance of solid lubricants. …”

“…Fleischauer et al [4] as well as Ehni and Singer [11] have shown 63 that the transfer can occur in the first pass. Sliney, using real-time optical analysis, has shown how loose MoS 2 debris can be extruded through the sliding contact and incorporated as both transfer film and track material [12].…”

“…low friction coefficient in terms of the plasticity/shear strength), the high endurance has never been accounted for. Furthermore, while MoS 2 provides endurant sliding, it is well known that most of the coating is lost early in life, both in sliding [2,3,4,5] and rolling [6]. How, then, does the remaining lubricant sustain sliding?…”

The Potential of Tribological Application of DLC/MoS2 Coated Sealing Materials

“…However, different oxidation rates at ambient condition were investigated, and it was found the crystallite orientation plays an important role in the oxidation process [45]. Oxidation leads to a higher friction coefficient, enhanced wear rate, and hence a shorter wear life [36,46]. The ratio of MoS 2 /MoO 3 in the reference coatings indicates that oxidation had occurred but the major portion is still MoS 2 .…”

Applications of Surface Science to Solid Lubricants

“…However, for optimum performance, it should be bonded to the surfaces to be lubricated through reaction of these same basal planes. The implications of this "paradox" have been the subject of numerous scientific and practical investigations [8][9][10][11][12], and a reasonable picture of the mechanism by which the material functions is beginning to emerge. It is emphasized that this understanding is forthcoming from the results of surface science studies, both spectroscopic investigations of electronic structure and bo.,ding and microscopic examinations of atomic arrangements, crystal structure, and morphology [13][14][15][16][17][18][19][20][21][22][23][24][25][26].…”