Semester of Graduation



Master of Science in Mechanical Engineering (MSME)

Document Type



To improve the tribological performance of contacting surfaces, different surface modification methods can be employed. Surface texturing and surface coating are examples of viable techniques developed for this purpose. Surface texturing involves creating micropatterns on the contacting surfaces while surface coating requires depositing a thin layer of a suitable material on the surface(s) to improve the component’s friction and wear characteristics. The performance of textured surfaces is affected by the geometric characteristic of textures.When dealing with surface coating parameters, the parameters of interests are the type of coating materials and their thicknesses.

The current study aims to experimentally study the friction variation as a result of surface texturing and surface coating on the piston rings by using a custom made piston cylinder machine. Of particular interest are their running-in behavior and the associated transient friction characteristics. A new type of texturing is also proposed for the application in piston oil control rings to reduce engine friction. Experimental studies are conducted to compare their performance of grooves with three structural angles (0, 30 and 60 degrees) and two different depths (5 and 10 microns). The optimum texture with grooves parallel to the sliding direction and depth of 5 microns was found to yield a 10% reduction in the friction force. Combination of the texturing and coating showed 12.5% improvement in frictional behavior when compared to cases when only one of them was applied.



Committee Chair

Khonsari, Micheal