Parametric Analysis of Different Grades of Steel Materials Used in Plastic Industries through Die Sinking EDM Process

1. Introduction

As the advanced materials are hard and have high strength, therefore machining them applying conventional techniques is rather difficult. To overcome this condition, nowadays the non-traditional techniques are used in modern manufacturing environment. Electrical Discharge Machining (EDM) is one such non-traditional machining process where material removal takes place by controlled erosion of electrically conducting material. The process is based on removing the material from the work piece by rapid and repetitive electric spark between the work piece and tool. The cathode tool and the anode work piece are separated by a dielectric fluid. As the tool and the work piece does not make direct contact during machining, so the machining stress, chatter and vibration do not occur. So this process can be used in machining of alloys having low machinability and high temperature strength resistance. It is also used to produce jobs having complex profiles and finish in aerospace, automotive industry and various types of dies and moulds in plastic industries. A successful optimization of process parameter is one of the significant aspect which is considered in the majority of non-traditional machining processes and especially in electric discharge machining process. The major factors influencing EDM process are Pulse on time (POT), Pulse off time (POF), Gap current (GI), Spark gap (SG), etc. and physical properties of electrode, work piece and dielectric fluid (Kiyak & Cakir, 2007). Optimal machining conditions are achieved by a detailed analysis off all the factors affecting the process and also the interaction between them. Design of experiments (DOE) methods has been used quite effectively in industrial applications to optimize manufacturing processes (Varun et al., 2012). The photograph of EDM setup is illustrated in Figure 1.

Figure 1.

Photograph of EDM setup