A Study on the Effect of Electrolyte Concentration on Surface Integrity in Micro Electrochemical Discharge Machining

Micro machining of nonconductive materials such as glass is critical as it has numerous applications in microsystems including biomedical devices, micro-reactors, micro-pumps, micro-accelerometers and MEMS. Electrochemical discharge machining (ECDM) is a promising process for the micromachining of glass. However, ECDM often inadvertently causes surface wrinkling and surface damages. This paper studies the effect of concentration of electrolyte in ECDM on the integrity of a micro machined hole surface. The study includes: analysis of surface roughness and micro-defects, microstructure by EDAX testing and hardness testing by nano indentation. It was found that lower electrolyte concentrations in ECDM enhance chemical etching that causes surface wrinkling.