To examine the effect of input parameters of rotary EDM on surface roughness of cryogenically treated Monel 400

Abstract

Rotary electric discharge machining (REDM) has an advantage over traditional EDM in that the tool speed can be varied to achieve better surface characteristics of machined components. Cryogenic treatment also improves the machining efficiency of non-traditional machining processes such as EDM. REDM is used in this study to establish a relationship between response parameters and control parameters while machining cryogenic treated alloy Monel-400 with a cryogenically treatedcopper electrode. The RSM approach was used to design experiments to investigate the effect of parameters such as tool speed, peak current, pulse on time, and duty cycle on surface roughness. An experimentally validated regression modal has been proposed. As per SEM examination, the typical surface produced for the setting of low pulse energy (at pulse on time:100 µs; Current:12 A; duty factor: 0.40; and tool rotation = 800 rpm) is found to be finer and showing shallow carters.