Abstract
Dimples is an important structure in the context of surface texturing due to its role in improving the heat transfer while minimizing wear and friction on sliding mechanical components. In this study, various sizes and shapes of dimple structures were fabricated on a cylindrical surface of a hyper eutectic aluminum silicon alloy (A390) using the turning process with the aid of a dynamic-assisted tooling (DATT), which was designed and fabricated in-house. The turning process was selected based on factors such as the capability of its machining process, low cost, minimum setup time, and green working environment. The dimples’ shapes fabricated in this study were short drop, long drop, and spherical, with widths of 397–920 µm, lengths of 2420–3261 µm, depths of 64–155 µm, and area ratios of 10–15.68%. The tribology test conducted on the samples confirmed that the coefficient of friction of these dimples in a hydrodynamic regime was 0.22–0.24 relative to the smooth surface's at 0.5, which is a maximum of 56% friction reduction. No microstructural changes were observed beneath the machined surface of the dimpled area and surface roughness (Ra) in the case of both dimple and non-dimpled surfaces. Dimple fabrication using the turning process is therefore recommended to the manufacturing industry if they intend to preserve material properties within friendly working environment(s).