Surface Integrity Evaluation of Modified EDM Surface Structure

摘要

Surface engineering, through either texturing or surface modification, for enhanced functionality is currently one of the most emerging research topic/technologies. This is mainly related to its huge commercial potential in terms of added value or product customisation, with applications extending from tooling, to mould & die, medical, food & drink, aerospace and others. With the recent advances in EDM generator design and process control, a number of commercial solutions were released by leading technology providers where it is deemed possible to apply a certain surface finish/structure, resulting in enhanced functionality (e.g. reduced friction or reduced/controlled adhesion) via the EDM process itself and without the need for a secondary operation. This paper investigates the surface integrity effects for this modified surface structuring concept (3DS). Experimental results showed that it was possible to reduce the friction coefficient (consequently ejection forces in the injection moulding process, for example) by as much as 60%, compared to samples machined using standard EDM settings while both having similar Ra values. 3DS samples however showed slightly lower fatigue performance which is likely to be the result of surface micro-cracking which appeared to be more prominent on these, compared to the standard EDM samples.