Determination of Crater Morphology and 3D Surface Roughness in Wire Electrical Discharge Turning of Inconel 825

Wire electrical discharge turning (WEDT) is a new non-traditional machining process developed to generate electrically conductive, difficult-to-machine, cylindrical materials. The present work seeks to propose a computational technique that utilizes the time integration effect to model the crater formed during the WEDT process of Inconel 825. A transient, two-dimensional numerical solver with user-defined function based on finite volume method facilitates to model the crater formation. The computational findings based on the proposed model act as the prerequisite for experimentation. A pulse-train analysis allows determining the discharge voltage, current and energy based on twenty-seven experimental trials conducted as per Box-Behnken design. The discharge energy associated with the spark leads to crater formation on the surface of the turned parts. The validation results of the proposed model with single-spark experiments were in good agreement with an average absolute error of 9.81% and 8.33% for depth and radius, respectively. Furthermore, the proposed model enables to determine the 3D surface roughness of the turned specimen. The validation results of Sa show a close agreement with the proposed model (average absolute error = 10.05%). Hence, the proposed model can act as a benchmark for further investigations on WEDT process of Inconel 825.