Study on Wire Electrochemical Machining of Nickel Base Alloy Using Fine Wire Electrode

Abstract

Abstract Nickel-based alloys represented by Inconel are materials with excellent high-temperature characteristics, and are widely used in the aerospace industry, such as aircraft and rocket engine parts. On the other hand, it is known as a typical difficult-to-cut material. Furthermore, in machining and electric discharge machining (EDM), the machining speed is slow and tool or electrode wear is a big problem. Meanwhile, electrochemical machining (ECM) using electrochemical reaction is not affected by the hardness of the material, does not generate a heat-affected layer on the workpiece surface, and has no tool wear. So, it is considered that ECM is suitable for machining difficult-to-cut materials. Therefore, in this study, focusing on the nickel-based alloy Inconel718 (Alloy718), we conducted a machining experiment using NaNO3 aqueous solution by wire ECM using a thin wire (mainly tungsten) as a tool electrode, and investigated the ECM characteristics. Wire ECM can be machined like wire EDM, and high-efficiency machining is possible by using a pulse power supply. As a result, it was found that increasing the voltage, electrolyte concentration, electrolyte supply pressure, and diameter of wire increases the current flowing between the electrodes and has the effect of promoting machining. In addition to simple cutting, the possibility of being effective not only for grooving but also for cutting complex shapes was shown.