Development of a unified thermal model for wire electrical discharge machining: integration of multi-discharge dynamics and plasma flush efficiency

Research efforts in wire electrical discharge machining (WEDM) process have been focused on optimising the process parameters so as for the productivity of the process to be increased. Although extensive research exists on various aspects of WEDM, comprehensive thermal modelling remains underdeveloped. This study addresses the gaps by integrating multiple existing thermal models to define a unified, multi-discharge model that accurately represents continuous and repetitive discharges. The new model incorporates critical factors such as Plasma Flush Efficiency (PFE) and the elliptical shape of craters, offering a more precise depiction of thermal phenomena and their correlation with process parameters. Implemented within a Finite Element Method (FEM) environment, the model was validated against experimental data from cutting tests on 316L stainless steel. The results demonstrated the model's capability to predict cutting geometry and process time with high accuracy, achieving a prediction error of 0.38% for cutting width and 12.20% for cutting time.