Machining of Small Curved Hole Using Electrochemical Machining Process

This paper describes the optimization of the tool design and machining condition in a small curved hole machining method. Curved holes can be machined using a flexible tool which can be curved by the hole being processed by the tool itself. The curvature of the hole can be determined by the tilt angle of the electrode tip attached to the end of the tool, and by the feed speed of the electrode. The experiments carried out using electrochemical machining showed that the proposed method could produce smooth curved holes without any special control. It was demonstrated that complicated curved holes with various curvatures were also produced successfully. These experimental results exhibited that the proposed method had a high potential as a processing method for curved holes in a metal mold. But, when this method was applied to small curved holes less than 6mm in diameter, it became clear that long time was necessary. In order to reduce this machining time, massive sludge has to be removed from the machining area effectively. A tool electrode device equipped with ultrasonic vibration function was designed and fabricated, for removal of the sludge from the bending cooling channel during machining. In consideration of an application to metal molds, it was found that a electrochemical machining attached ultrasonic vibration could reduce machining time of curved holes. (C) 2018 The Authors. Published by Elsevier B.V.