Investigating the influence of rotational speed in wire electric discharge machining of cylindrical workpieces: an experimental and simulation study

Wire electrical discharge machining (WEDM) is a non-conventional machining process renowned for precision in machining complex profiles, especially in high-strength and hard materials. This process also found other functions in machining cylindrical workpieces, known as wire electrical discharge turning (WEDT). The material removal mechanism of this process is based on electrical discharges, and evaluating the productivity of the continuous process to a great extent depends on the material removal of individual single discharges. In order to study the influence of rotational speed in material removal of erosion in cylindrical workpieces, theoretical and experimental studies of each single spark are necessary. This comprehensive study delves into the influence of rotational speed in WEDM processes applied to cylindrical workpieces. The research includes a series of single discharge experiments, and introduces a computational fluid dynamics (CFD) thermal model. The developed thermal model demonstrates the capability to predict the material removal rate of a single discharge with an error of 8.6% relative to experimental data. Furthermore, the investigation extends to continuous erosion studies, analyzing the material removal rate under varying rotational speeds. The overall material removal rate decreases 13% due to the declining material removal rate of each single discharge. Additionally, a removal efficiency parameter of erosion of cylindrical workpieces is introduced to provide an evaluation of the process and the influence of crater overlaps. The removal efficiency for various rotational speeds ranges between 22 and 24%, influenced by the proportion of normal discharges and the efficiency of crater overlaps.