Effect of Peak Current on Material Removal Rate for Electrical Discharge Machining of Non-Conductive Al₂O₃ Ceramic

Abstract:

Electrical discharge machining (EDM) is a non-conventional machining process where materials are removed by the thermal energy exerted from series of electrical sparks. This process is applied for machining of non-conductive alumina (Al₂O₃). The workpiece is covered with the adhesive copper foil to initiate the initial spark between the workpiece and the tool electrode. A pyrolytic carbon (PyC) layer is generated on workpiece surface by dissociating kerosene dielectric after the machining of initial copper assisting electrode (AE) layer. In this study, experiments were performed by varying the peak current and keeping other parameters constant in order to investigate the effect of peak current on material removal rate (MRR) in EDM of Al₂O₃. The results showed that the lowest and the highest values of peak current were 1.1 A and 1.3 A, respectively. Material cannot be removed due to insufficient PyC layer generation for any values of peak current less than 1.1 A or more than 1.3 A. From the results, it is also observed that the MRR is increased when higher peak current values are used. MRR was found to be 0.052 mm³/min at peak current 1.1 A and it was found to be 0.132 mm³/min at peak current 1.3 A.

• Periodical: Advanced Materials Research (Volume 845)
• Pages: 730-734
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.845.730
• Online since: December 2013
• Authors: M.A. Moudood*, A. Sabur, Yeakub Ali Mohammad, I.H. Jaafar
• Keywords: Assisting Electrode, Conductive Layer, Electrical Discharge Machining (EDM), Material Removal Rate (MRR), Non-Conductive Ceramic, Peak Current

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