Effects of nanopowder TiO2-mixed dielectric and rotary tool on EDM

Abstract

There are some methods to increase the performance of electrical discharge machining (EDM) process such as adding the powder to dielectric, using the rotational tool, and using the magnetic field. Also, combination of these methods can be performed. Many researchers investigated on the effect of the different powder types on EDM performance. However, only a little research used the nanopowder TiO2. Also, there is not any study on combination of powder-mixed EDM with a rotary tool. In this paper, the effect of adding the TiO2 nanopowder and rotational tool on the EDM process was studied and the effects of parameters such as the percentage of the concentration of the powder, spark energy and the speed of tool rotation on the material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) were investigated. As a result, it was indicated that the combination of the nanopowder and rotational tool simultaneously can improve the efficiency of EDM. Tool rotational speed up to 200 rpm can enhance machining stability. Also, for adding the powder, there is an optimum and up to 1 g/l, it affects the MRR. Finally, a comparison between the workpiece SEM images of this method and conventional EDM showed that the surface roughness improves. Moreover, the magnetic field 0.38 T can get the debris away from machining gap easier and increases the MRR and TWR and improves the surface roughness in this method.