Comparative study for material removal rate, surface finish and electrode wear rate on die sinking edm

The electrical discharge machining (EDM) is one of non conventional machining process where the erosion of the work piece take place based on the the1mal energy between the electrode and the work piece. Two different work piece materials were machined using die sinking EDM to study the characteristics of each material using copper electrode. Two different work piece materials were used, aluminum and copper and the dimension for each is 100 mm length, 50mm width and 6mm thick. The Sodick CNC EDM die sink will be used as the main equipment in this project. To get the best result, the selections of parameters play a main role in producing good surface finish quality, high removal rate (MRR) and less electrode wear ratio (EWR). High electtode wear ratio (EWR) and the lower material removal rate is some of the problems in EDM machine that will decrease machining productivity. There are four different pulse cunent that will be tested (8 , 12, 16 and 20 ampere) with four pulse on time in micro second (50, 100, 150, and 200) and the reference voltage and pulse on time are kept constant 22 Volt. There are sixteen engrave will be formed in each sample. Dielectric fluid is used is kerosene and the polarity or machining type is positive. At the end of this study the optimal performance parameters will be defined and determining which mate1ial gives highest mate1ial removal rate, less surface finish as well as the conditions that give less tool wear rate (TWR). The result obtained indicating that the material removal rate MRR and TWR are increased with the increase of cun-ent. This is because the higher cun-ent means higher and stronger spark that generates or melt more material from the work piece. The result shows that pulse duration has a little effect on the MRR. But regarding the tool wear ration TWR the results show a decrease of the TWR along with the increase of pulse duration this is because of the presence of carbon layer that precipitated on the surface of the electrode and the thickness of this layer increased with the increase of pulse duration and in tum decrease the TWR. Regarding the comparative study, the result showed that aluminum has higher MRR compared with copper, this is due to the fact that aluminum has lower melting point compared with copper. And regarding the TWR, the results showed that the copper has little amount of tool wear when machined using copper electrode, this is because the copper has higher thennal conductivity compared to aluminum who has higher TWR when machined using same copper electrode. The higher the1mal conductivity means more the1mal energy this work piece can can-y and also means more facilitating the the1mal energy will be diffused which maintain the tool wear