Surface texturing by micro ECM for friction reduction

Abstract

Surface texturing with micro-dimples is a known method for friction reduction under lubricated sliding contact, and various machining techniques have been researched and developed in order to fabricate micro-dimple patterns. However, previous fabrication methods possess several problems, such as causing thermal damage on the workpiece or limiting the available workpiece geometry. In micro ECM, micro features can be machined without any resulting thermal or mechanical damage. From this perspective, micro ECM has certain advantages over surface texturing. Also, micro ECM is applicable to non-planar workpieces. In this research study, micro ECM with microsecond pulses was applied in order to fabricate a micro-dimple pattern. The machining characteristics were investigated in fabricating micro dimples on AISI 440C specimen. On the basis of the experimental results, a 300 mu m dimple pattern was successively produced on the AISI 440C specimen. A friction test on the textured specimen was performed and compared with a non-textured specimen. The enhancement of frictional performance was successfully demonstrated experimentally.