The EN24 and EN42 materials were machined by the electric discharge machine
(EDM). The study aimed to optimize the input variables for the multiple outputs,
such as metal removal rate (MRR), tool wear rate (TWR), and surface roughness.
The machining of the metal is essential to analyze the surface quality and the
production rate. The MRR is a prediction of the production rate and surface
roughness resembling the quality of the surface. The input variables were
current (A), pulse on time (ton), and pulse duty factor (T). The
three levels of current were 3A, 6A, and 9A. The ton time was
selected as 30 μs, 50 μs, and 70 μs. The pulse duty factors were selected as 4,
5, and 6. The Taguchi optimization techniques are used to optimize process
parameters. The L9 orthogonal array was selected for the process. ANOVA analysis
was employed to check the rank of the input parameters relative to the output.
The maximum MRR were at 9A, 70 μs, and 4 duty factor for the EN24. The best MRR
were at 9A, 70 μs, and 5 duty factor for the EN42. The contribution of
ton was maximum compared in the tool wear analysis. The optimum
value of tool wear was at 6A, 70 μs, and 4 duty factors for the machining of
EN42 and EN24. The surface analysis for EN24 was yielding at 9A, 70 μs, and 4
duty factor, and 9A, 70 μs, and 5 duty factors for the EN42. The maximum
contribution of pulse on time for surface finish for machining both the
materials. The scanning electron microscopy (SEM) analysis also analyzed the
surface quality.
