Investigation of the Influence of Process Parameters of Wire Electrical Discharge Machining Using Coated Brass on the Surface Roughness of Inconel 718

Wire electrical discharge machining (WEDM) is widely used to cut complex and intricate shapes with superior surface finish and accuracy. In the WEDM process, the material is eroded from a workpiece through a series of electric discharges occurring in the sparking gap between the workpiece and a tool electrode. The main problem in the WEDM process is to choose proper material for the wire electrode, which should have many properties to ensure the required cutting speed and high-quality surface finish. To order to the current requirements, new geometrical and metallurgical solutions of wire electrodes are intensively developing, for instance: coated electrodes. The purpose of the experimental research was to investigate the influence of process parameters of wire electrical discharge machining using zinc coated brass wire on the surface roughness. The workpiece material used in the present investigation was Inconel 718. The study was carried out with a design experimental methodology. Input parameters were pulse time t(on), time interval t(off) and wire speed WS. To characterize the surface texture after WEDM process, surface roughness Ra was described. The bearing capacity curve was designated in order to characterize the tribological properties of the surface depending on input parameters. Regression equations and their graphical interpretation were determined for the purpose of analyzing the influence of processing parameters on the Ra roughness parameter.