Relationship between electrode diameter and wear ratio in scanning electrical discharge machining

AbstractTo achieve better precision of features generated using the micro-electrical discharge machining (micro-EDM), there is a necessity to minimize the wear of the tool electrode, because a change in the dimensions of the electrode is reflected directly or indirectly on the feature. This paper presents a novel modeling and analysis approach of the tool wear in micro-EDM using a systematic statistical method exemplifying the influences of capacitance, feed rate and voltage on the tool wear ratio. The association between tool wear ratio and the input factors is comprehended by using main effect plots, interaction effects and regression analysis. A maximum variation of four-fold in the tool wear ratio have been observed which indicated that the tool wear ratio varies significantly over the trials. As the capacitance increases from 1 to 10 nF, the increase in tool wear ratio is by 33%. An increase in voltage as well as capacitance would lead to an increase in the number of charged particles, the number of collisions among them, which further enhances the transfer of the proportion of heat energy to the tool surface. Furthermore, to model the tool wear phenomenon, a regression relationship between tool wear ratio and the process inputs has been developed.

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The Analysis of Processing Factors for Electro-Arc Machining

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.470.585 ◽

2013 ◽

Vol 470 ◽

pp. 585-588 ◽

Cited By ~ 1

Author(s):

Min Zhang ◽

Qin He Zhang ◽

De Zheng Kong ◽

Yang Ren

Keyword(s):

Tool Wear ◽

Pulse Duration ◽

Rotational Speed ◽

Electrical Discharge ◽

Electrical Discharge Machining ◽

Tool Material ◽

Wear Ratio ◽

Tool Wear Ratio ◽

Input Parameters ◽

Processing Factors

Electro-arc machining is similar with traditional electrical discharge machining (EDM) while the pulse duration of electro-arc machining is longer than that of EDM. The longer discharge was named arcing, and the arcing could lead to high material remove rate (MRR) and low tool wear ratio (TWR). Processing factors including discharge medium, tool polarity, tool material, voltage and rotational speed were chosen as input parameters on MRR and TWR. Taguchis method was used to evaluate their effects. All of the five processing factors had effects on MRR and TWR. The effects and the mechanism are also discussed.

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Ringing Effect and Reversed Current Analysis of RC-Pulse Generator in Electrical Discharge Machining

Materials Science Forum ◽

10.4028/www.scientific.net/msf.770.183 ◽

2013 ◽

Vol 770 ◽

pp. 183-188 ◽

Cited By ~ 1

Author(s):

Min Zhang ◽

Qin He Zhang ◽

De Zheng Kong ◽

Xue Bai

Keyword(s):

Tool Wear ◽

Electrical Discharge ◽

Pulse Generator ◽

Electrical Discharge Machining ◽

Wear Ratio ◽

Tool Wear Ratio ◽

Effect Theory ◽

Low Efficiency ◽

Ringing Effect ◽

Reversed Current

RC-pulse generator has a simple structure and it is easy to be made and repaired. Especially RC-pulse generator can provide high frequency and low energy discharges. Therefore RC-pulse generators are used in micro-EDM field. But its high tool wear ratio and low efficiency restrict its applications. Ringing effect is considered to have effect on the defects. This research was done to study the ringing effect in electrical discharge. Taguchi method was used and discharge curves of voltage and current were recorded and analyzed. Ringing effect plays a key role in discharges and reversed current. A waveform model established with ringing effect theory is almost the same as the waveforms recorded in the experiment. Reversed current exists in almost a half time of discharge period which is the representation of ringing effect. Suitable process parameters can reduce reversed current and proper improvements could eliminate reversed current which will reduce the tool wear ratio and increase the efficiency in RC-pulse generator.

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