Quantification of a Lubricant Transfer Process that Enhances the Sliding Life of a MoS2 Coating

A lubricant transfer process that enhanced the wear life of a MoS2 coating has been identified and quantified. A steel ball sliding against a coated steel flat in reciprocating motion produced reservoirs at the turnaround part of the track ends, then emptied them, to provide replenishment similar to what is expected of liquid lubricants. The dynamics of the process were inferred from measurements of material loss and/or buildup in the track and on the ball; measurements were performed with Michelson interferometry and energy dispersive x-ray spectroscopy.