Comparative Evaluation of Untextured and Textured Surfaces for Wear, Wettability and Friction Characteristics

Reduction of frictional losses by changing the surface roughness in the form of surface textures has been reported as an effective method in reducing friction in the boundary regime of lubrication. LASER based microtexturing has been mostly used to create these texture patterns and it is reported that it can reduce the frictional resistance by ~20-50%. However, the use of laser-based techniques for texture preparation led to residual thermal stress and micro cracks on the surfaces. Hence, the current study emphasizes using conventional micromachining on piston material (aluminium alloy Al4032) to overcome this limitation. Three variations of semi-hemispherical geometries were prepared on the surface of aluminium alloy with dimple depths of 15, 20 and 40 µm and dimple diameters of 90, 120 and 240 µm. Prepared textured surfaces with untextured surfaces are compared in terms of wear, wettability, and friction characteristics based on Stribeck curve behaviour. Conventional micromachining achieved improved dimensional precision and minimized thermal damage. Textured surfaces have shown reduced friction when lubrication is in a mixed and boundary regime due to increased wettability. The results of this study will be analysed and reported for comparative evaluation of textured and untextured surfaces for reduced friction in the piston-ring-liner interface.