A Study on Kerf Width of EN47 Steel in WEDM

The current experimental work investigates the influence of various process variables during wire-cut elecro-discharge machining (WEDM) ofEN47 spring steel on width of kerf. Taguchi’s L 27 orthogonal array design of experiment is used to determine experimental runs corresponding to three levels of each of four factors viz. pulse-on time, wire feed, pulse-off time and gap voltage. Optimal condition for minimising kerf width is tried to find out within the experimental range. Analysis of variance (ANOVA) is employed to evaluate the significant process variable and the interaction terms to control kerf width. Finally, validation test is conducted to justify importance of the selected design. Signal to noise ratio of kerf width at optimal condition has been improved by 7.58% over the initial condition. Gap voltage and pulse off time are found to be the most significant parameters while pulse-on time has only moderate influence. Optimal condition is 8ps pulse-on time, 10µ s pulse-off time, 6m/min wire feed and 150V gap voltage.