1M. Tech. student from Galaxy Global Group of Institutions (GGGI), Dinarpur, Ambala, Haryana
2Assistant Professor working in Galaxy Global Group of Institutions (GGGI), Dinarpur, Ambala, Haryana
3Assisitant Professor working in Swami Devi Dyal Institute Of Engg. & Technology (SDDIET), Barwala, Haryan
Online published on 19 April, 2019.
Electrical discharge machining (EDM), is a thermal based machining process whereby a desired shape is obtained by using electrical discharges. In this process Material is removed from the workpiece by a series of rapidly recurring current discharges between two-electrodes, separated by a dielectric liquid and subject to an electric voltage. One of the electrodes is called the tool-electrode, or simply the "tool" or "electrode, " while the other is called the workpiece-electrode, or "workpiece." The process depends upon the tool and workpiece not making actual contact. When the voltage between the two electrodes is increased, the intensity of the electric field in the volume between the electrodes becomes greater than the strength of the dielectric (at least in some places), which breaks down, allowing current to flow between the two electrodes. As a result, material is removed from the electrodes. Once the current stops (or is stopped, depending on the type of generator), new liquid dielectric is usually conveyed into the inter-electrode volume, enabling the solid particles (debris) to be carried away and the insulating properties of the dielectric to be restored. In this study we will discuss the effect of different machining parameters like voltage, current, pulse on time, pulse off time on the response parameters mainly on tool wear rate. the study will be made with four different values of input parameters. The other parameters such as duty cycle, polarity, spark gap are kept constant. In this experiment mild steel is selected as work piece and copper rod with 10mm diameter is taken as tool electrode. The layout of design of experiment is based on Taguchi L16 orthogonal array and analysis of variance (ANOVA) is used to investigate the results obtained from Taguchi. From the result it is found that the tool wear rate is directly proportional to the current and pulse on time. As the range of current and pulse on time increases, the tool wear rate also increases. This is due to that as the current and pulse on time increases, the heat energy also increase which further results of more metal to be melt from work piece and tool. For the response parameter i.e. tool wear rate, the voltage and pulse off time have not much effect.
