Optimization of Process Parameters in Electrical Discharge Machining of OHNS by using RSM's Response Optimizer

Electric discharge machining (EDM) is a non-traditional machining process; it is a well-established machining option in many manufacturing industries throughout the world. There are no physical cutting forces between the tool and work piece while removing the material, it only uses thermal energy to machine electrically conductive parts regardless of hardness has been its distinctive advantage in the manufacturing industries. (OHNS) Oil Hardening Non Shrinking Die Steel is an ideal type of oil hardened steel economical for manufacturing Industries. It is generally used for Blanking and Stamping dies, Gauging tools, Wood working tools etc. This paper reports the results of an experimental investigation carried out to study the effects of machining parameters such as current, voltage and pulse on time on material removal rate and tool wear rate in electrical discharge machining of OHNS by using copper electrode. The process has been successfully carried by Response surface methodology (RSM) and model adequacy is carried out by using Minitab software. While RSM's D-Optimal Method is used to solve the multi-response optimization. To validate the optimum levels of the parameter, confirmation run was performed by setting the parameters at optimum levels. It is observed that voltage is most significant parameter for material removal rate and tool wear rate followed by pulse on time and current.