Phase Transformations and Electrothermal Effects in EDM-Machined Steel: Surface Topography, Crater Morphology, and Debris Evolution

This study investigates the physical and microstructural properties of EDM-machined steel under varying electrical discharge machining (EDM) conditions. An experimental approach is adopted to evaluate the influence of pulse time (Ton), rest time (Toff), and discharge current (I) on material removal rate (MRR) and surface roughness (Ra). The effect of discharge energy on crater formation, debris evolution, and microstructural transformations is analyzed. Surface integrity is assessed through microscopic roughness analysis, crater morphology measurements, and X-ray diffraction (XRD) to reveal phase transformations induced by electrothermal effects.