Title: Effect of deep cryogenic treatment on machinability of Inconel 718 in powder-mixed EDM

Authors: Chinmaya P. Mohanty; Siba Sankar Mahapatra; Manas Ranjan Singh

Addresses: Department of Mechanical Engineering, Faculty of Science and Technology, IFHE University Hyderabad, India ' Department of Mechanical Engineering, National Institute of Technology, Rourkela, India ' Department of Mechanical Engineering, Silicon Institute of Technology, Bhubaneswar, India

Abstract: The study presents experimental investigation to assess influence of cryogenic treatment of electrodes on machinability in powder-mixed electrical discharge machining (PMEDM). Response surface methodology is used to extract maximum process related information with less number of experimental runs. The machining characteristics of the process are evaluated in terms of material removal rate (MRR), electrode wear ratio (EWR) and surface roughness which are function of machining parameters viz. open circuit voltage, discharge current, pulse-on-time, duty factor, concentration of fine graphite powder and cryogenically treated work tool pair. The study reveals that discharge current, pulse-on-time, concentration of powder and work-tool pair exhibit significant effect on all the performance measures. It is also observed that treatment to both the electrodes results in more beneficial in comparison to treatment of either the tool or work piece. Finally, a novel multi-objective particle swarm optimisation algorithm (MOPSO) has been proposed in order to achieve optimal Pareto front.

Keywords: powder-mixed EDM; deep cryogenic treatment; DCT; MOPSO; NSGA II; surface roughness; electrode wear ratio; EWR; material removal rate; MRR.

DOI: 10.1504/IJMMM.2017.086164

International Journal of Machining and Machinability of Materials, 2017 Vol.19 No.4, pp.343 - 373

Received: 09 Mar 2016
Accepted: 07 Jul 2016
Published online: 28 Aug 2017 *

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