Effects of Electrode Polarityon SKD61 Steel Surface Properties in Powder Mixed Electrical Discharge Machining

Metal powder or alloy powder is suspended in a suitable dielectric fluid during electrical machining dischagre (EDM) is very effective in improving the productivity and quality of the machined surface. Thus, the researches in this area have been very interesting. This paper introduces the investigated results influencing the electrode polarity on the quality of the machined surface after EDM with powder mixed in dielectric fluid (PMEDM). Titanium powder, SKD61 hot die steel and copper and graphite electrodes were used for the research. These parameters were selected to evaluate the quality of the machined surface such as and thickness of the heat-affected layer, chemical composition, topography and microhardness. The results showed that the electrode polarity in EDM with titanium powder mixed in oil dielectric fluid can significantly affect the quality of the machined surface.