A novel power source for high-precision, highly efficient micro w-EDM

Abstract

The study presents the development of a novel power source for high-precision, highly efficient machining of micropart microstructures using micro wire electrical discharge machining (w-EDM). A novel power source based on a pluri resistance–capacitance (pRC) circuit that can generate a high-frequency, high-peak current with a short pulse train is proposed and designed to enhance the performance of micro w-EDM processes. Switching between transistors is precisely controlled in the designed power source to create a high-frequency short-pulse train current. Various microslot cutting tests in both aluminum and copper alloys are conducted. Experimental results demonstrate that the pRC power source creates instant spark erosion resulting in markedly less material for removal, diminishing discharge crater size, and consequently an improved surface finish. A new evaluation approach for spark erosion ability (SEA) to assess the merits of micro EDM power sources is also proposed. In addition to increasing the speed of micro w-EDM by increasing wire feed rates by 1.6 times the original feed rate, the power source is more appropriate for machining micropart microstructures since there is less thermal breaking. Satisfactory cutting of an elaborate miniature hook-shaped structure and a high-aspect ratio microstructure with a squared-pillar array also reveal that the developed pRC power source is effective, and should be very useful in the manufacture of intricate microparts.

Classification and comparative study of EDM pulse generators

“…Apart from the important topologies described in the previous subsections, researchers have proposed some EPGs, which are modified forms of some topologies described above. For example, Chen and Chen [51] have proposed a pulse generator, which is a modified form of transistorised pulse generator topology T3. Han et al [52] have proposed a transistorised iso‐pulse generator, which can provide pulses with a discharge duration of 30–80 ns and hence improve MRR as compared to the RC type pulse generators.…”

Micro-electrical discharge machining of 3D micro-molds from Pd40Cu30P20Ni10metallic glass by using laminated 3D micro-electrodes

“…As a result of this method, the tool wear ratio is within 5% and the mushroom-shaped spherical structures (with 1 mm diameter) were fabricated in N-BK7 optical glass. To enhance the performance of micro-wire electronic discharge machining (WEDM), Chen and Chen designed a pluri resistance-capacitance (pRC) circuit [12]. This novel power source based on a pRC circuit successfully fabricated a rook-shaped structure and high-aspect-ratio microstructure.…”