On the behaviour of an oil lubricated fretting contact

Tribological effects of fullerene (C60) nanoparticles added in mineral lubricants according to its viscosity

“…3 Shima et al (1997) reported that the friction coefficient with low lubricant viscosity was lower than that of high lubricant viscosity in fretting wear due to the penetration of the lubricant into the contact interface, and to the removal of wear debris particles from the contact interface. 4 Tu et al (2004) reported that the friction coefficient was higher for a system with higher lubricant viscosity in the hydrodynamic lubricant regime. Lubricant viscosity had no effect on the friction coefficient in the boundary lubricant regime, as expected.…”

A friction energy approach to quantifying lubrication under fretting sliding

“…Fretting as oscillatory motion with small amplitudes and very low velocity (even at high frequencies) leads to the situation when dynamic fl uid lubrication during sliding is unrealisable. The fretting regimes under dry and lubricated conditions were presented fi rstly in pioneering work of R. B. Waterhouse et al 1,2 As it has been made in earlier studies by Waterhouse, the effect of lubricant on fretting depends on its ability to penetrate into the contact zone, and to recover (if squeezed out) to form boundary fi lm and reduce the oxygen access. The rate of replenishment of oxygen to the surface is proportional to the diffusivity of the lubricant, which is approximately inversely proportional to the viscosity.…”

“…N total number of cycles ∑Ed RIP total energy dissipated in the running-in period ∑Ed RIP_SSL energy dissipated in the running-in period if the value of Ed = Ed SS ∑Ed SS total energy dissipated in steady-state ∑Ed SS_SSL energy dissipated in steady-state if the value of Ed = Ed SS L RIP lubrication parameter for running-in period, equal to 1 for perfect lubrication L SS lubrication parameter for steady-state, equal to 1 for perfect lubrication Q friction force, tangential force Q* tangential force amplitude δ amplitude of displacement δ g sliding amplitude μ coeffi cient of friction A = πa 2 area of contact a radius of contact u sliding velocity η 0 viscosity of bulk lubricant h oil∞ thickness of the oil in vicinity of the contact σ s surface tension in vicinity of the contact E RC = πa 2 σ s energy needed to replenish the contact…”

An investigation of fretting behaviour of several synthetic base oils

“…In fact, literature survey shows many investigations on the surface finish of material, surface coatings, lubricating oil viscosity and boundary lubrication properties as well as some mechanical parameters under mineral oil conditions [1][2][3][4][5][6][7][8]. Rough contact surface helped to retain some oil, so the friction and wear may be decreased [1,2].…”

“…Rough contact surface helped to retain some oil, so the friction and wear may be decreased [1,2]. Combination of surface coating and lubrication could improve tribological performance [3,4].…”