Sidewall Insulation of Microtool for Electrochemical Micromachining to Enhance the Machining Accuracy

Abstract

This paper presents a new approach for sidewall insulation of microtool by dip coating using liquid solution made of polymer and resin dissolved in isopropyl alcohol and use of acetone for opening the front end of the microtool. This method can also be used to remove the previously applied coat completely so that the microtool can be reinsulated again for the reuse. To investigate the effectiveness of insulating film, in-situ fabricated tungsten microtool of 104 µm diameter was insulated with 4.5-µm thick film by proposed method. Microfeatures like microhole and microgroove were machined by electrochemical micromachining (EMM) using uninsulated microtool and insulated microtool on stainless steel. The machining accuracy of the microfeatures machined were compared in terms of overcut and taper angle generated on microfeatures. In this way, 33.78% reduction in radial overcut of microhole and 58.64% reduction in width overcut of microgroove were observed. Taper angle was reduced from 40.57° to 18.00° and 58.39° to 25.20° for microhole and microgroove, respectively. The influence of sidewall insulation on shape accuracy, machining rate, and surface roughness of machined microfeatures was also investigated.

Keywords:

• Accuracy
• EMM
• Insulation
• Microtool
• Overcut
• Roughness
• Sidewall
• Taper

Notes

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