Effect of Surface Topography on ZDDP Tribofilm Formation During Running-in Stage Subject to Boundary Lubrication

Abstract

Experimental investigations have been conducted to study the effects of surface topography on ZDDP (zinc dialkyldithiophospahte) chemical tribofilm formation during runningin stage under boundary lubrication conditions. The scope of presented work has been limited and focused on reciprocating motion under boundary lubrication to simulate upper and lower dead center of piston ring movement, which is prone to adhesive wear failure. Several surface topographies were designed and fabricated to measure, compare coefficient of friction and ZDDP time critical tribofilm formation. Rubbing surfaces and their corresponding tribofilms were characterised by SEM and EDX. Mechanisms of surface topography effects on ZDDP time critical tribofilm formation is presented and discussed. Results from this study have demonstrated that the surface topography has a significant influence on the ZDDP time critical tribofilm formation during running-in process and corresponding wear performance. This research provides an opportunity to augment anti-wear performance under boundary lubrication condition. This can be achieved by optimising surface morphology design to influence the formation of anti-wear tribofilms during the running-in stage.In turn, this will result in interacting components' service life enhancement and significant cost savings from mitigated wear.

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

“…The tests were conducted under three different temperatures, i.e., 60, 100, and 140 ℃. It is known that the surface roughness changes rapidly during running-in yet remains relatively stable thereafter [62]. Therefore the surface roughness of the ring and liner samples after running-in was measured, which were 0.408 and 0.571 µm, respectively and they were used as input values of the multidisciplinary coupling model.…”

On-Line Feedback Control of Sliding Friction of Metals Lubricated by Adsorbed Boundary SDS Films

“…The former is the resistance caused by the current line contraction; the latter is caused by the contact surface being covered by some layers with poor electrical conductivity [24]. With the in-depth study of lubricant additive mechanism under boundary lubrication, ECR has been widely used to analyze the formation process of tribochemical reaction film on-line [25,26]. Previous investigations have indicated that ECR can characterize the formation and failure of the adsorption film on the metallic surfaces of tribopairs.…”