Geometric simulation of electro-erosion edge honing: Insights into process mechanisms

A serious limitation of sink electrical discharge machining is the rapid geometric degeneration of sharp features due to localized wear. Electro-erosion edge honing is a novel process that creatively exploits this phenomenon for the edge preparation of cutting tools. This paper presents a geometric model of the process that can accurately predict the profiles of both symmetric and asymmetric edges that are prepared in the process. Numerical simulation of the model quantifies the concept of relative duty in the context of the process, and offers unique insights into process mechanisms. In particular, the critical influence of the wear ratio in determining the prepared edge being either rounded or chamfered is clarified, in consideration of the trajectory of successive discharge trains. The work further enables an understanding of the influence of initial edge defects on the processed edge, and presents guidelines for optimizing edge quality.