Investigation of machining characterization of solar material on WEDM process through response surface methodology

The photovoltaic sector needs a high-throughput slicing method that produces minimal waste to meet rising demand. Wire electric discharge machining (WEDM) has emerged as an alternative slicing method in recent research efforts. Polycrystalline silicon is sliced using the WEDM process with a zinc-coated electrode of Ø0.25 mm in diameter. Experiments were planned and conducted according to Box Behnken’s design of experiments. As inputs, seven different process parameters were used: pulse on time (PONT), pulse off time (POFFT), peak current (PC), spark gap voltage (SGV), wire feed (WF), wire tension (WT), and water pressure (WP). Response parameters measured were cutting speed (CS), surface roughness (SR), and kerf width (KW). Various process parameters have also been analyzed with ANOVA methods for predictive modeling. Based on experimental data, this study determines the appropriate optimal solutions via desirability functions. During the WEDM process, the PONT, POFFT, PC, and SGV significantly influence the discharge energy on the sliced surface. As a result of this study, CS of 0.78 mm2/min, SR of 2.87 μm, and KW of 0.70 mm were observed at the optimal settings of PONT of 119 μs, POFFT of 42 μs, PC of 38A, SGV of 36V, WF of 3 mm/min, WT of 2 kg and WP of 6 kg/cm2. Surface morphology was determined using scanning electron microscope and Energy dispersive X-ray to investigate the surface characteristics.