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The effect of cylinder liners on engine performance is substantial. Typically, the cylinder surfaces were plateau honed. However, recently additional dimples or grooves were created on them. This work discusses the tribological impacts of textured cylinder liner surfaces based on a review of the literature. The results of the experimental research obtained using test rigs and fired engines were critically reviewed. In addition, the results of the modeling are shown. Circular oil pockets and grooves perpendicular to the sliding direction of piston rings of small depths were typically used. Surface texturing of the cylinder liners governs lubrication between the cylinder liner and the piston ring by an increase in oil film thickness near the reversal points leading to reductions in friction force and wear and in the fired engine to a decrease in fuel consumption and to an increase in power or torque. The correct texturing pattern ensures a decrease in the oil consumption, blow-by, and emissions of the internal combustion engine compared to plateau-honed surfaces. Considerations of future challenges are also addressed. The volume of lubricant reservoir in surface topography, called oil capacity, should be a substantial parameter characterizing textured surfaces. [ABSTRACT FROM AUTHOR]

Laser surface texturing (LST) is widely explored for modifying the surface topography of various materials. In this study, a detailed investigation of laser textured surfaces produced on austenitic stainless steel (AISI 304) was carried out. Three different textures (square, parallel, perpendicular) were produced by a Ti sapphire laser. The processed surfaces were characterized by surface morphology, phase structure, microhardness, surface roughness, and wettability. A ball-on-disk tribometer was used to study the tribological performance of both untextured and textured samples. The experimental observations demonstrate that LST improves both surface wettability and surface roughness. Average surface roughness (Ra) was increased by 350% and the contact angle was reduced from 43° to 22°. The textured surfaces show a lower coefficient of friction and better wear resistance than the untextured surface. Out of the investigated patterns, the square textures exhibited a maximum reduction of 68% in the friction coefficient and a 50% lower wear rate. [ABSTRACT FROM AUTHOR]

The frictional capacity of rubber-tired metros decreases over time under the action of metro traffic. It is well known that the texture of rolling tracks contributes to evacuate water from the tire/track interface and generate friction forces. There is then a need to understand the evolution under traffic of the texture of rolling tracks to optimize their maintenance in terms of surface texturing. This paper investigates the friction and wear of steel rolling tracks subjected to laboratory polishing tests. Specimens are extracted from real metro tracks. Different initial textures obtained from different initial treatments of the surfaces are studied. Polishing and friction measurements are performed. During the polishing process, the surface topographies are measured at different polishing states and functional volumes and texture descriptors evaluated. Results show that the surface asperity's height and sharpness decrease with the number of polishing cycles. Also, the wear characterized by the difference in terms of material volumes between the initial and polished states, increases with the polishing duration. This evolution is composed of two phases corresponding respectively to transient and stationary wear. The evolution of wear volume during the stationary phase is in agreement with Archard's wear law. Tight correlation is found between friction and wear volume. [ABSTRACT FROM AUTHOR]