학술지명 : Journal of Micromechanics and Microengineering
발행국가 : 영국
발표일자 : 2009년 3월
SCI여부 : SCI
제목 : Micro electrical discharge drilling of tungsten carbide using deionized water (초경합금의 미세방전드릴링)
저자:송기영, 정도관, 박민수, 주종남
내용 : 탈이온수를 사용해 초경합금에 미세 방전드릴링을 수행할때, 전해부식을 막기위하여 방전회로와 전극 형상에 대해 연구함.
Micro electrical discharge machining (micro EDM) is an effective machining method for cobalt-bonded tungsten carbide (WC-Co); however, this material is susceptible to electrolytic corrosion when deionized water is used as the working fluid with a dc power source for the RC circuit. In this study, a bipolar pulse power source and a triangular electrode were used in order to reduce the electrolytic corrosion phenomenon during micro EDM using an RC discharge circuit. A bipolar pulse power source reduces the positive polarity period of the workpiece by periodically alternating the polarity of the workpiece and electrode and decreases the average gap voltage at the machining gap. Therefore, electrolytic corrosion, which is a type of electrochemical reaction on the positively charged workpiece, is reduced by these electrical conditions. The triangular electrode has a smaller side area as compared with the cylindrical electrode. Since the electrolytic corrosion is an electrochemical reaction between the side of the electrode and the surface of the workpiece, the small side area of the triangular electrode could reduce these reactions. With the aid of the bipolar pulse power source and the triangular electrode, an electrolytic-corrosion-free hole could be machined on the WC-Co workpiece using deionized water.