Thermal modeling, simulation, and experimental validation of micro electric discharge machining of tungsten carbide (WC)

Abstract

Tungsten carbide is a material that is widely used in tools and dies applications due to its high hardness, excellent toughness, and wear resistance. However, machining this material using conventional methods can be very challenging due to its exceptional properties. In such cases, electrical discharge machining can be used as an alternative method for machining this material. The aim of this study is to examine the thermal properties of EDM of tungsten carbide, both through finite element modeling and experimental conditions. The study aims to evaluate the temperature distribution in tungsten carbide during EDM die sinking. This is accomplished by drilling 0.5mm diameter and 1mm deep micro holes using micro-drilling processes. Seven experiments were performed using an EDM die-sinking machine, and a 3D axis symmetrical model was created and simulated using the COMSOL Multiphysics heat transfer module. The temperature profile of tungsten carbide material during a single spark machining was obtained by considering only 30% of energy in the form of Gaussian distribution that gets transferred to the workpiece. The temperature profile of this model was then used to estimate the material removal rate. By comparing the numerical and experimental results, it was found that there was only a 4.8% average percentage error, indicating very close agreement between the numerical and experimental results. The findings suggest that the finite element method of the COMSOL Multiphysics heat transfer module can accurately predict and simulate the real-time results of EDM machining. These results could be useful for EDM machine operators for pre-estimating MRR and maximum temperatures before proceeding with the actual machining.