Sliding energy of textured surfaces via pendular tests

Abstract

Purpose Surface texturing can improve the tribological performance of contacting sliding surfaces under different contact and lubrication conditions, which has been proved both numerically and experimentally. This study aims to suggest a new methodology to evaluate the tribological behavior of textured surfaces using an adapted pendular scratch tester. Design/methodology/approach A Charpy-type tester was adapted to meet conditions that are relevant for sliding surfaces. The test rig was used to evaluate low carbon steel textured surfaces produced via maskless electrochemical texturing. The textures were composed of 100 pockets with an average diameter of 200 µm of and variable average depths (1.5, 3.5 and 7 µm). The tests were performed under dry and lubricated conditions for smooth and textured surfaces. The lubricated tests simulated a starved condition by applying a drop of lubricant. Findings For starved lubrication, surface texturing reduced the sliding energy when compared with smooth surfaces. This was attributed to the pocket’s ability to provide an additional supply of lubricant, as well as a reduced amount of plastic deformation around the pockets during sliding of the indenter. However, under dry sliding conditions, no significant effect of surface texturing was detected. Originality/value A new evaluation methodology was proposed, using single-pass pendular sliding of a spherical indenter to measures the energy absorbed during sliding, which was referred to as sliding energy. The measurements are repeatable and can detect sliding energy differences between smooth and textured surfaces.

Synergetic effects of surface texturing and solid lubricants to tailor friction and wear – A review

“…The ability of surface textures to control friction and wear under dry and lubricated conditions has been exhaustively investigated for more than three decades. Under lubricated conditions, the main mechanisms behind the improved performance of textured surfaces are the increase of the hydrodynamic film thickness and load bearing capacity [19,37,[50][51][52], increased lubricant supply [53][54][55][56] and increased inlet suction [53,57]. Gropper et al presented a thorough review of textured surfaces under hydrodynamic lubrication [17].…”

Brazilian Tribology: origin, status quo and future perspectives

“…Activities related to tribology and surface engineering at the Federal University of Rio Grande -FURG started in 2016 when Prof. Henara Costa moved from LTM/ UFU to FURG, culminating with the creation of the Laboratory of Surface Engineering (LabSurf) in 2019. The works span from surface engineering techniques such as surface modifications [113,280,[320][321][322][323][324][325][326][327][328][329][330][331][332] and different coating technologies [112,113,[333][334][335] to their effects on surface topography [102,103,121,326,[336][337][338], surface hardness [339][340][341], machinability [2], formability [337,342,343], corrosion [335,[344][345][346], tribological performance [13, 50-52, 113,280,320,322,333,337,347,348] and tribo...…”

“…Surface modification technologies have mainly focused on changing microstructure [340,341] and surface topography [90-93, 95, 110, 113, 320, 322-324, 326] to achieve surface functionality. The proposition of novel techniques for surface texturing with reduced cost and increased speed, when compared with conventional texturing technologies such as laser texturing, has had a great impact on making the use of surface texturing more cost-effective, in particular, maskless electrochemical texturing (MECT) [92,93,95,322,323,326,331], photochemical texturing [90, 91, 93] and inkjet printing [93]. Although the surface texturing studies have been primarily experimental, collaboration with LFS/USP and Imperial College London has enabled the numerical modelling of textured surfaces [280].…”

ZDDP Tribofilm Formation from a Formulated Oil on Textured Cylinder Liners

“…A recent review has established the current developments and trends in laser texturing technology [30]. Alternatively, Maskless Electrochemical Texturing (MECT) is a simple, cheap, and fast technique to texture conductive surfaces, although it is not a commercial technique yet [31]. MECT uses localized micro-electrochemical machining of an anodic surface against a patterned cathode, but the individual workpieces do not require previous masking [32] as an advantage over other electrochemical techniques, such as through-mask electrochemical micromachining (TMEMM) [33][34][35].…”