Investigations into performance of dry EDM using slotted electrodes

Abstract

Dry EDM is an emerging EDM technology, which uses gas as dielectric fluid. Due to low density of gaseous dielectric, the process experiences i) unconstrained plasma expansion thereby reducing the effective material removal rate (MRR) and ii) inefficient disposal of debris. This work proposes use of electrodes with peripheral slots to provide more space for the flow of dielectric for effective debris disposal and consequently improve MRR. In this regard, a comprehensive experimentation using Taguchi L 16 orthogonal array has been planned initially to optimize the number of peripheral slots on the electrodes, and then to understand the effect of the slots on material removal, tool wear, oversize and depth achieved as a function of processing conditions. It is observed that the optimum number of peripheral slots on electrode for effective debris evacuation is four for the electrode configuration used in this work. The statistical analysis shows that in dry EDM, discharge current (I), gap voltage (V), rotational speed (N) and pulse off-time (T off ) control MRR. Also, use of slotted electrodes significantly reduces the electrode wear rate, and attachment of debris particles on the electrodes.

High-speed dry electrical discharge machining

“…The electrode is not a thin-walled tube used in previous studies in dry EDM [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The use of thin-walled electrode in their studies is attributed to the fact that the machining gap is extremely small and the efficiency of expelling debris will be low when a thick electrode is used.…”

“…Using electrodes with peripheral slots [10] Providing more space for the flow of dielectric for effective debris disposal…”

“…However, their MRR improvements are limited and the equipment used in their experiments is complex. To obtain effective debris disposal and improve MRR, Puthumana and Joshi [10] slotted the electrode. To combine the advantages of gas and liquid processing, Kao et al [11][12][13] conducted a number of explorations in near-dry EDM.…”

The Methodologies Adopted To Improve the Machinability in Die-Sinking EDM

“…Trials proved that it can offer cleaner and safe environments than conventional machining. Puthumana and Joshi [20] used slotted electrode in EDM process. Gas was used as die electric fluid which is supplied through the electrodes.…”

Fabrication of Superhydrophobic Metallic Surface by Wire Electrical Discharge Machining for Seamless Roll-to-Roll Printing

“…In this study, a simple and large-scale patterning method was realized by direct patterning on the metal surface using wire electrical discharge machining (WEDM), a metal processing method, in order to produce the micro/nanostructure in one-step fabrication. WEDM is widely used in the metal processing field and is a precise processing technique that can create shapes on surfaces in numerous micro-units [9][10][11][12][13][14]. Moreover, since the WEDM process induces discharge on the metal surface during processing, the nano-sized roughness is automatically created, and the multi-scale shape can be obtained in one step.…”