Micro-hole Maching of Copper Using the Electro-discharge Machining Process with a Tungsten Carbide Electrode Compared with a Copper Electrode

Micro Eletro Discharge Milling for Microfabrication

“…It was also observed that material removal depth was inversely proportional to feed rate (Lim et al, 2003). MRR can be increased in both positive and negative polarity by rotating the toolelectrode (Her and Weng, 2001). Higher MRR was obtained for low ultrasonic vibration frequency combined with tool rotation (Ghoreishi and Atkinson, 2002).…”

“…It was suggested to use low conductive or higher resistive dielectric to ensure low R a and R y (Liao et al, 2004). Use of rotating electrode was helpful for high shape accuracy and higher MRR but it caused higher surface roughness (Her and Weng, 2001). Formation of crack is a challenge in EDM.…”

Sub-nanosecond monitoring of micro-hole electrical discharge machining pulses and modeling of discharge ringing

“…The choice of polarity can greatly affect the wear of wire electrodes. Electrode wear is expected to be high under negative polarity [7]. This property is used to blunt the tip of the electrode, a procedure known as electrode dressing.…”

“…The parasitic components induce a reverse current [3], which can lead to inferior surface roughness and excessive electrode wear [7,8]. The reverse current is also observed in both spark and arc pulses during this microhole EDM study.…”

“…Tungsten is the most common electrode material because of its high melting temperature (3370 1C) and low tool wear rate. The tungsten wire electrode is centerless ground [7] to achieve uniform size and can be as small as 30 mm in diameter. A scanning electron microscopy (SEM) micrograph of the 0.15 mm diameter injector micro-hole is shown in Fig.…”