ABSTRACT
In this chapter, the machining performance of tungsten as electrode was inspected by performing a series of experiments on SUS-316L workpiece. Material removal rate (MRR) and surface roughness (SR) were chosen as output responses and statistically evaluated via analysis of variance (ANOVA). The higher thermal conductivity and melting point of tungsten result in very negligible tool wear rate (TWR) under the selected experimental conditions. The significance of input machining parameters on output responses was decided on the basis of p-value (typically ≤ 0.05) and mean variation of the S/N ratios. The maximum MRR (7.028 mg/min) was observed at the parametric combination of peak current of 28A, pulse on-time (P-on) of 90 µs, and pulse off-time (P-off) of 60 µs, whereas the minimum value of SR (0.397 µm) was observed at the peak current of 20A, the P-on of 60 µs, and the P-off of 60 µs. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to scrutinize the topography and phase transformation of electric discharge-machined surfaces, respectively. Additionally, Minitab software was used to generate a regression model, which confirmed via the confirmatory test to associate the relationship between the input parameters and output responses.
KeywordsEDM; SUS-316L; Material removal rate; Surface roughness; Regression model.
