Hybrid Micromachining of Glass Using ECDM and Micro Grinding

Micro electrochemical discharge machining (ECDM) is a well-known machining process that achieves 3D micro structures in glass-type material. However, a rough surface is the main disadvantage of this process. In the present work, a hybrid process of ECDM and micro grinding using polycrystalline diamond (PCD) tools is investigated. Micro structures in glass workpieces were machined by ECDM and then ground by PCD tools to improve the surface quality. Micro grinding by PCD tools is used to overcome the rough surfaces that are generated by sparks in ECDM. The characteristics of micro grinding, such as the surface roughness of the tool, depth of cut, and feedrate, using PCD tools for ECDM structures were investigated. It is experimentally shown that the grinding process under PCD tools reduces the surface roughness of ECDM structures from a few tens of a mu m to 0.05 mu m R-a, and the total machining time of the hybrid process is less than a third compared to that under a conventional grinding process.