Abstract
There is comprehensive work on the tribological properties and lubrication mechanisms of oil lubricant used on textured surfaces, however the use of grease lubrication on textured surfaces is rather new. This research article presents an experimental study of the frictional behaviours of grease lubricated sliding contact under mixed lubrication conditions. The influences of surface texture parameters on the frictional properties were investigated using a disc-on-ring tribometer. The results showed that the friction coefficient is largely dependent on texture parameters, with higher and lower texture density resulting in a higher friction coefficient at a fixed texture depth. The sample with texture density of 15% and texture depth of 19 μm exhibited the best friction properties in all experimental conditions because it can store more grease and trap wear debris. The reduction of friction is mainly attributable to the formation of a stable grease lubrication film composed of oil film, transfer film and deposited film, and the hydrodynamic pressure effect of the surface texture, which increases the mating gap and reduces the probability of asperity contact. This result will help in understanding the tribological behaviour of grease on a textured surface and in predicting the lubrication conditions of sliding bearings for better operation in any machinery.
Highlights
With the rapid development of industrialization, friction and wear reduction between two sliding bodies requires the constant presence of a lubricant within the contact area in order to reduce and control friction and wear, reducing energy consumption, extending service life of mechanical systems and enhancing their reliability and safety [1,2,3]
Applications of laser surface texturing on contacting parts such as piston ring-cylinder liners [8], cams/tappets [9], bearings [10], seals [11] and cutting tools [12,13] can result in a significant reduction in friction and wear
Under the present experimental conditions, the frictional behaviour of grease under textured surfaces in sliding conditions can be explained with the properties of grease and the influences of surfaces in sliding conditions can be explained with the properties of grease and the influences of surface texture parameters
Summary
With the rapid development of industrialization, friction and wear reduction between two sliding bodies requires the constant presence of a lubricant within the contact area in order to reduce and control friction and wear, reducing energy consumption, extending service life of mechanical systems and enhancing their reliability and safety [1,2,3]. In many situations the lubricant is automatically fed into the contact area by the relative movement of the friction pair itself. Laser surface texturing, which was pioneered by Etsion et al [5,6] as a surface-engineering technique, has emerged as a viable technology to keep grease where it is needed and to maintain lubrication for longer periods of time in order to address these concerns [7]. Applications of laser surface texturing on contacting parts such as piston ring-cylinder liners [8], cams/tappets [9], bearings [10], seals [11] and cutting tools [12,13] can result in a significant reduction in friction and wear. Surface texture may be positive, in that it protrudes out of the surface, or negative, Lubricants 2017, 5, 42; doi:10.3390/lubricants5040042 www.mdpi.com/journal/lubricants
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
