ABSTRACT
Surface engineering plays a crucial role in enhancing the tribological performance of rubbing surfaces. Sliding contacts experience heavy friction losses due to the presence of thin oil films at critical load-speed conditions. Surface modification techniques such as surface texturing and coatings are most widely used to reduce sliding friction and wear of components. Also, the selection of appropriate lubricant is also important in deciding lubrication performance, thus enhancing the tribological behavior. The present research focuses on positive surface texturing (protrusions) to assess friction and wear characteristics of sliding contacts under dry as well as lubricated conditions. Different lubricants were tested on a four-ball tester for the selection of appropriate lubricant to enhance the lubrication performance at the contact. After selection of lubricant, surface textures in the form of circular-shaped protrusions were produced on a substrate through a chemical etching process. The textures having 1 mm diameter and varying heights of 5, 15, 25, and 35 μm were developed. The sliding tests were conducted on pin-on-disc equipment at different speeds. The results depicted that almost all the textured surfaces improved the tribological behavior compared to untextured surfaces in dry as well as lubricated conditions. Besides, a texture height of 25 μm exhibited a lower frictional coefficient and wear rate among all the tested samples. Moreover, at a higher speed of 0.78 m/s, minimal friction and wear were noticed.
