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

Abstract

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.