Investigations on Magnetic Field Assisted Electrochemical Discharge Machining Process

Electrochemical discharge machining (ECDM) process is an arising unconventional machining process for the micromachining of non-conducting materials. During the ECDM process, surface damages, machining continuity at higher depths and hole over cut (HOC) are the main issues during drilling. Previous researchers reported that gas film thickness, debris evacuation and electrolyte replenishment are the prime reasons for the lack of surface quality and lower hole depth. The present investigation has employed a magnetic field during the machining process, and they found a positive effect on the above-mentioned issues. Lorentz force was produced during the machining process, and created a circular motion of the electrolyte around the tool electrode. This phenomenon helped to control the gas film thickness, debris flushing, and electrolyte replenishment at the tool end. In the present work, the authors used a 1300 Gauss Fe-based ceramic permeant ring magnet. Magnetic field strength for both south and north poles was measured using a digital Gauss meter. A high-speed image-capturing camera was used to understand the bubble generation, gas film formation, and debris evacuation during the machining process. The authors applied both north and south-pole magnetic fields for the investigation of the machining process and compared the results with the conventional ECDM process. Better results in surface quality, hole depth, and HOC were achieved with the south pole magnetic field compared to the traditional ECDM process.

Keywords: Borosilicate glass, ECDM, Gas film, Lorentz force, Magneto hydrodynamic effect, NaOH.