Some innovative surface texturing techniques for tribological purposes

Abstract

This paper reviews methods for texturing surfaces for tribological applications and presents some innovative methods that could make surface texturing more cost-effective. Possible texturing methods were identified and classified according to their physical principles. This involved identifying existing texturing methods and also led to proposals for new possible methods. Three innovative texturing methods with low cost and high texturing speed are then presented: (i) a simpler and cheaper version of photochemical texturing, (ii) maskless electrochemical texturing, and (iii) masking surfaces by ink-jet printing followed by etching. From these, maskless electrochemical texturing was the cheapest and fastest, but the minimum size of the texture features was the largest. Ink-jet printing followed by etching is an alternative that may potentially provide a good combination of cost and resolution, but the texturing time depends on the surface area. Then, an attempt was made to delimit tribological applications where the use of such processes could be beneficial, based on analysis of experimental results of their tribological evaluation. These showed that the methods proposed could be particularly suited for components with contact areas larger than the width of the texture features under either hydrodynamic lubrication or starved lubrication.

Looking into a laser textured piston ring-liner contact

“…This approach can be applied to a wide range of materials including metals [16], polymers [17], ceramics [18]. However, due to the limitations related to production times and manufacturing costs, other innovative production methods are being explored -these, along with their advantages over LST, have recently been reviewed by Costa and Hutchings [19].…”

Combined friction and wear reduction in a reciprocating contact through laser surface texturing

“…This has enabled us to measure and characterise the wear behaviour accurately and to remove the influence of initial surface roughness on texture behaviour. The pockets were produced using Laser Surface Texturing (LST) [4]. Also known as laser honing, this method employs an ultra-fast picosecond laser which emits optical pulses with a duration of 10 ps, frequency of 10 kHz and wavelength of 355 nm, and power of 5 micro joules.…”

“…Currently, surface texture is receiving increased attention due to the need to improve the energy efficiency of automotive contacts [2], which, in turn, is driven by stricter CO2 emission limits [3], and the pressing issues of climate change. It is also the case that methods of producing texture are becoming cheaper and more accurate [4]. Despite all this, there is still a lack of firm evidence regarding the mechanisms by which surface texture affects tribological performance and this is limiting its development and application.…”

Lubricant film thickness and friction force measurements in a laser surface textured reciprocating line contact simulating the piston ring–liner pairing

“…However, due to the high manufacturing costs and speed limitations of LST, alternative texturing methods for tribological surfaces are becoming increasingly prevalent. A recent study by Costa and Hutchings [27] investigates and classifies existing texturing techniques and explores a variety of innovative methods which may be employed in the future.…”