Electrolytic removal of recast layers on micro-EDM microstructure surfaces

Abstract

Micro-EDM technology is widely used in the field of micro-fabrication due to its low cost, non-contact, and other processing characteristics. The EDM method involves molding parts by implementing the principle of melting metal at a high temperature, which results in a thin recast layer on the surface of the workpiece. The recast layer can critically affect the surface topography and mechanical properties of the part, making it a potential safety hazard in fields such as aerospace and medical sciences. The purpose of this paper is to apply the electrolytic removal method of the recast layer on different microstructures, and thus solve the problem of on-line, orientation, and quantitative removal of recast layers on complex three-dimensional surfaces. In this work, the main components of the recast layer were analyzed to push the main principles and influencing factors of its participation in the electrolytic reaction. Then, the electrolysis removal experiments of the recast layer on the surface of foundation structures were carried out, and different processing strategies were proposed for different microstructures. Finally, the micro-EDM-ECM–integrated processing technology was applied, resulting in a micro-grooved structure of surface roughness Ra less than 0.3 μm.