An investigation of fretting wear behaviors of bonded solid lubricant coatings

Three different bonded solid lubrication coatings, i.e. a bonded MoS2 coating, a bonded graphite coating and a bonded polytetrafluoroethylene (PTFE) coating, on AISI E4142 steel were studied in order to compare their fretting wear behaviors and mechanisms. Fretting tests were conducted on the steel substrate and the coatings under the same conditions. Dynamic analyses were performed in combination with examinations through scanning electron microscopy (SEM) and X-ray diffraction (XRD). Experimental results show that the three coatings have excellent anti-friction and wear-resistant performances under fretting condition, and strongly modify fretting regime behaviors compared to that of the non-coating condition. Crack propagation and coating fatigue are believed to be the predominant mechanism of particle detachment layer by layer.