A scuffing model considering additive depletion in boundary lubrication

Abstract

Purpose This paper aims to propose a new scuffing model caused by the depletion of additives in boundary lubrication condition. Design/methodology/approach The differential equation governing the distribution of additive content in the fluid film was used. This formula was derived from the principle of mass conservation of additives considering the consumption due to surface adsorption of wear particles. The occurrence of scuffing was determined by comparing the wear rate of the oxide layer with the oxidation rate. Findings If the additive becomes depleted while sliding, the scuffing failure occurs even at a low-temperature condition below the critical temperature. The critical sliding distance at which scuffing failure occurred was suggested. The experimental data of the existing literature and the theoretical prediction using the proposed model are shown to be in good agreement. Originality/value It is expected to be used in the design of oil supply grooves for sliding bearings operating under extreme conditions or in selecting the minimum initial additive concentration required to avoid scuffing failure under given contact conditions.

Impact of oil ageing on gear scuffing in hybrid dual-clutch transmissions

“…Contaminations such as wear particles and reactive surfaces can influence oil ageing through catalytic effects that accelerate oxidation 26,35 or through adsorption of additives. 36 While Oil B, C and D show a similar correlation between the iron content detected by inductively coupled plasma with optical emission spectrometry (ICP-OES) according to ASTM D4951 and DIN 51399-1, respectively, and the remaining SLC, Oil A behaves differently. Oil A aged with FZG A gears shows a decrease in SLC already at lower iron contents and is less dependent on the applied specific work.…”

Experimental and Numerical Study of the Mixed Lubrication Considering Boundary Film Strength

“…In 2018, Xu et al [ 24 ] proposed a boundary lubrication model considering the dynamic effect of boundary films by analyzing the generation rate and removal rate of boundary films. In 2019, Lee et al [ 25 ] derived a boundary film failure model based on the principle of additive mass conservation and concluded that the depletion of the additive caused the failure of the boundary film during sliding. In 2021, Lyu et al [ 26 ] suggested that the higher shear energy of the fluid would lead to the collapse of the boundary film based on the thermal fluid film thinning effect.…”

Scuffing failure analysis based on a multidisciplinary coupling model and experimental verification

“…The absence of this layer has been suggested as the root cause of scuffing [12]. Moreover, there are some other scuffing hypotheses, e.g., the wear debris scoring [13], additive depletion [14], oxidative decomposition of the lubricant [15] and so on.…”