THERMAL MODELLING AND EXPERIMENTAL VALIDATION OF ELECTRIC DISCHARGE MACHINING PROCESS

Abstract

Electric Discharge Machining process has found wide application in manufacturing industries for machining of enormous complex shapes of all electrical conductive materials. The EDM process generates spark by transferring the thermal energy between workpiece and electrode. The present study develops a finite element model for M2 high speed tool steel and simulate on ANSYS. M2 grade of HSS have good wear resistance and hardness, which is why it is used as cutting tools in industries and make it suitable for EDM machining. The objective of this study is to calculate material removal rate on EDM process and effects of three input parameters viz. discharge current, pulse on time and duty factor on material removal rate. EDM is a very complex process, it involves thermal, mechanical chemical, electrical and various mechanisms. So, to fully understand the process performance, it is necessary to develop a theoretical model for solving the process. ANSYS 15.0, a finite element solver has been used to obtain the temperature distribution on workpiece for single spark. The transient thermal analysis of 2D axisymmetric model considering temperature dependent properties of workpiece and Gaussian distribution of heat flux has been used to calculate temperature distribution and material removal rate. The experiments have been performed with varying current, pulse on time and duty factor on an EDM machine to measure the material removal rate. Comparison has been done between presented model results and experimental results and theoretical results are found quit compatible with the experimental results