Machinability of cryogenically treated workpiece (AISI M2 HSS) in edm process

Abstract

The present experimental investigations are to evaluate the machinability of cryogenically treated AISI M2 HSS with copper as Tool in EDM process. The Experiments are performed to study the effects of input parameters such as Discharge current, Pulse on time, Duty cycle and Gap voltage on MRR, TWR and Radial overcut. Nowadays use of cryogenic treatment in machining is increasing day-by-day because the properties necessary for Tool we get after cryogenic treatment, except impact strength. After Cryogenic treatment there is improvement in the properties of the material such as electrical properties, thermal properties, brittleness and hardness. In this present investigation deep cryogenic treatment was done at -185°C for 36 hours on work piece (AISI M2 HSS) without tempering. Compared to conventional tool and work piece, the cryogenically treated work piece shows average increase 3.56% in MRR, the TWR is about 12.76%. The Radial overcut for cryogenic treated work piece is more than conventional EDM. The SEM images shows that machined surface of conventional EDM surface is better than cryogenically treated work piece.