Influence of roughness on ZDDP tribofilm formation in boundary lubricated fretting

Abstract

Influence of initial surface topography on tribofilm formation in ZDDP lubricated contact was analysed. A small displacement fretting tests with sinusoidal motion were carried out in classical sphere/plane configuration. A range of surfaces with different initial roughness were prepared by milling and grinding processes. Tests were carried out using variable displacement method where amplitude of imposed displacement was gradually increased after every 1000 cycles from 2 to 30 µm. The surfaces after tribological tests were measured by interferometric profiler. Main findings confirm that initial roughness has a significant influence on antiwear tribofilm formation in boundary lubricated contact. Tribofilm forms faster and require less energy to activate in case of rough surface obtained by milling process than in case of smooth grinded surface. However, in contact lubricated by oil with ZDDP additive a significant transfer of material occurred from plane to sphere specimen.

Microstructural and Chemical Characterization of the Tribolayer Formation in Highly Loaded Cylindrical Roller Thrust Bearings

“…However, roughness generally plays an important role for the tribolayer formation in boundary lubricated contacts. Tribolayers usually form faster and require less energy input to be formed for a rough surface compared to a smooth surface [4]. Lubricant mineral oil mixed with ZDDP additive, C3C4-alkyl-chain with 0.05% P, 2 h sliding test.…”

“…The friction reducing properties of ZDDP are mainly attributed to an increased load support, beneficial mechanical properties by preferential shearing, removal of Fe 2 O 3 particles, and finally the surface protection against corrosion. The growth and removal rate of the tribolayers is a highly dynamic process [4].…”

Influence of Steel Surface Composition on ZDDP Tribofilm Growth Using Ion Implantation

“…Effective tribofilm formation relies on the interaction of ZDDP with a rubbing, solid surface, and to understand and improve the anti-wear performance, it is essential to consider the additive and surface in combination. Previous investigations have shown that ZDDP tribofilm formation is affected by the solid surface properties, including hardness [1][2][3] and roughness [4][5][6], as well as chemical composition [7,8]. All these surface properties must be taken into account when studying mechanisms of tribofilm formation.…”

Analysis of surface roughness morphology with TRIZ methodology in automotive electrical contacts: Design against third body fretting-corrosion

“…However, it is known that high surface quality promotes friction damage [32]. Kubiak et al [30,[33][34][35] report that surface geometry influences friction conditions due to the increased contact force on rough surfaces [36]. This makes it possible to control the friction between the partial slip (only the outer contact area is exposed to the slip, while the central area remains in an adhesive state) and the total slip (the entire contact surface is exposed to the slip).…”