Accuracy Improvement Techniques in Electrochemical Micromachining (EMM)

Abstract

Electrochemical micromachining (EMM) has several advantages over its competitive micromachining techniques, and hence, it is one of the best micromachining techniques applied in various fields. However, further investigations are required to augment the machining accuracy for overcuts, taper formation, profile accuracy, and surface excellence, to discover the utility of EMM for various applications. Generally, microstructures like microholes, microslots, microgrooves, and 3D microfeatures are machined on various metallic components by EMM. Geometrical profile, dimension, and tribology of machined microfeatures mainly affect the performance as well as life of these components. Therefore, machining of such microfeatures of few tens to hundreds of microns with correct shape profile and better quality is ever demanding area for exploration. Availability of electrolyte at inter-electrode gap, removal of slush and hydrogen gas bubbles from machining zone, stray-current control, and microtool feed rate control to maintain uniform inter-electrode gap are the major challenges for the researchers to increase the machining accuracy. Machining accuracy can also be upgraded by selecting proper shape and size of the microtool, by insulating the sidewalls of the microtool, and also by utilizing the innovative machining strategies. In addition to these techniques, controlling and optimizing influencing process parameters of EMM and hybrid electrochemical micromachining are some of the areas by which machining accuracy can be enhanced in EMM.