Analysis and Synthesis of Influence of Tool-Electrode Materials in Electric Discharge Machining of M2 High-Speed Tool Steel

Molybdenum high-speed steel particularly termed as M2 High-Speed Tool Steel specifically in the manufacture of Milling Cutters, Thread roll Dies, and other emerging areas like automobile, defense, aerospace, bio-medical segments has an extensive applications. Machinability studies for this type of the material are having extreme significance. M2 steel has the higher toughness and inhomogeneity, resulting in decreased machinability. These features of the M2 steel demands an advanced machining process. Electric Discharge Machining (EDM), a versatile process in machining the advanced materials, in which the thermal conductivity and the electrical resistivity of the work piece and the tool electrode plays a key role in determining the performance of the process. In the present work, relative studies has been conducted on the EDM of M2-Steel utilizing two differentelectrodes namely graphite and copper. Taguchi's L27orthogonal array was utilized to design the experiments. Peak current (IP), pulse-on time (TON), pulse-off time (TOFF), and voltage (V) were selected as the input process parameters.The performance of the machining process is evaluated by measuring the three different responses namely material removal rate (MRR), electrode wear rate (EWR), and surface roughness (SR). The experimental results indicated that the Graphite tool electrode ensued 12.84 % higher MRR,and 11.59% lower SR than the copper tool electrode. Copper tool electrode resulted in a 3.61 % lesser electrode wear rate (EWR)