Finite Element Modeling of Single Spark Material Removal and Heat Flux Distribution in Micro-Electro Discharge Machining Process

Abstract

Micro-Electro Discharge Machining (Micro-EDM) is a prominent non-conventional machining process. In this process, material removal takes place due to the melting and evaporation of electrode materials. The process gained a lot of research interest due to its ample potential in machining metallic materials and simple construction. In this paper, a thermal model has been developed to study the single spark material removal in Micro-EDM process. Single spark material removal study provides the significant information about optimization of the input parameters such as pulsed DC voltage, input current, spark duration, material removal rate of the electrodes, and area of heat distribution on the workpiece. ANSYS multiphysics is used to study the thermal analysis to determine the temperature and heat flux distribution on the workpiece. Silver material is used for both the electrodes. To validate the model, experiments were designed and conducted on tailor-made Micro-EDM setup. From the simulation study, it was found that for the pulse-on time (spark duration) of 40 µs, the material removed for single per spark was 7.53 ng per spark and the maximum heat flux obtained was 2614.2 × 108 W/m2. Simulation results were compared with the actual machined results. Crater profile was analyzed by Veeco Wyko NT1100 non-contact surface profilometer. The material removed by the single spark is obtained up to 8.16 ng. There was 8% error variation between simulation and experimental study. This may be due to assumptions made during simulation study and the presence of elemental impurities.