Mehran University Research Journal of Engineering and Technology (Jan 2017)
Effect of Electric Discharge Machining on Material Removal Rate and White Layer Composition
Abstract
In this study the MRR (Material Removal Rate) of the aerospace grade (2024 T6) aluminum alloy 2024 T6 has been determined with copper electrode and kerosene oil is used as dielectric liquid. Discharge energy is controlled by electric current while keeping Pulse-ON time and Pulse-OFF time as constant. The characteristics of the EDMed (Electric Discharge Machined) surface are discussed. The sub-surface defect due to arcing has been explained. As the surface material of tool electrode and workpiece melts simultaneously and there are chances of the contamination of both surfaces by the contents of each other. Therefore, the EDS (Energy Dispersive Spectroscopy) of the white layer and base material of the workpiece was performed by SEM (Scanning Electron Microscope) at the discharge currents of 3, 6 and 12 amperes. It was conformed that the contamination of the surface of the workpiece material occurred by carbon, copper and oxygen contents. The quantitative analysis of these contents with respect to the discharge current has been presented in this paper.
