Effect of current and pulse duration on machining performance using different size of electrode diameter during electrical discharge machining (EDM) of AISI D2 tool steel

Abstract

The important output in measuring the performance of electrical discharge machine is the material removal rate, electrode wear rate and the quality of machined surface. Higher material removal rate is always preferred in the manufacturing of parts or product. However, as other machining method, high removal rate will result in higher electrode wear rate and rougher surface. Since each type of workpiece material possess different properties and characteristics, the outcome of the performance measures would also varies. Therefore, there are still great needs to investigate the relation between the machining parameters and performance measures The main interest of this study is to investigate how the performance measures are influenced by various setting of machine parameters when machining the AISI D2 tool steel. Those machine parameters are discharge current and pulse duration. The value of discharge current used is 12, 16 and 24 A. Pulse duration is also set to different values that are 100, 200 and 400 μs. Besides that, different electrode diameters that are 5, 7 and 10 mm are used to study its significance to the performance of machining process. Copper is selected as the electrode material in the machining process while kerosene as dielectric fluid. The total of 27 experiments was conducted to collect the data. From the observation, it is found that discharge current and pulse duration are part of the factors that influenced the performance of EDM. The use of different electrode size also has some significance in the machining process. However, the results shows that there are no specific value or input parameters settings that are capable of optimising all the output parameters. Therefore, compromise between the various outputs parameters are required to determine the input settings.