Influence of machining parameters on surface texture and material removal rate of Inconel 718 after electrical discharge machining assisted with ultrasonic vibration

Abstract

Dynamic development of new difficult-to-machine materials requires the adaptation of new efficient methods of their machining. One of the modern materials widely used in the aviation and space industry is Inconel 718. Due to its hardness (44 HRC) and low thermal conductivity, this material is difficult to machine by conventional treatment. Electrical discharge machining (EDM) is often used to machine materials regardless of their physical and mechanical properties. The EDM process is a non-traditional manufacturing process in which material is removed from a workpiece through a series of electric discharges occurring in the sparking gap between the workpiece and a tool electrode. To increase the performance in the EDM, it is still developing different varieties of hybrid processes. The purpose of the experimental research was to investigate the influence of machining parameters on surface texture and material removal rate (MRR) of Inconel 718 after electrical discharge machining assisted with ultrasonic vibration of the tool electrode (EDM+US). The study was carried out with an experimental methodology design. Input parameters were discharged current I and pulse duration ton. Parameter Ra was designated for each machined surface. In the research, mathematical models and their graphical presentations describing the influence of selected processing parameters on the MRR and surface roughness.