A highly energy-efficient milling of Inconel 718 via modulated short electric arc machining

Abstract

An excellent and advanced manufacturing method named modulated short electric arc machining (M-SEAM) was proposed in this study to solve the problems of low machining efficiency and high specific energy consumption (SEC) for difficult-to-machine materials in the traditional electric discharge machining (EDM) and electric arc machining (EAM) process.The discharge channel is established by the collision between the electrode and the workpiece. The arc spreads and moves as the electrode rotates. Moreover, the energy balance equation of the modulated arc was established, which revealed that the volt-ampere characteristic is resistive when the frequency of pulse voltage tends to infinity in the steady state, the arc had a large relative thermal inertia, and two stable operating points were analyzed. M-SEAM processing was performed using graphite and Inconel 718 as electrode and workpiece materials, respectively. The results showed a maximum MRR of 49,020 mm3/min, and the relative electrode wear rate (REWR) and SEC were limited to 0.92% and 50.21 kJ/cm3, respectively. The peak current was 1940 A, and the maximum discharge time for a single arc was 328.56 ms.