Title: Experimental investigations into electrical discharge deep hole drilling of Inconel 718 using copper-tungsten electrode

Authors: P. Kuppan; S. Narayanan; A. Rajadurai

Addresses: School of Mechanical and Building Sciences, VIT University, Vellore – 632014, India. ' School of Mechanical and Building Sciences, VIT University, Vellore – 632014, India. ' Department of Production Technology, Madras Institute of Technology, Anna University, Chennai – 600 044, India

Abstract: This paper reports an experimental investigation on deep hole drilling of Inconel 718 by electrical discharge machining (EDM) process. The important process parameters such as peak current, pulse on-time, duty factor and electrode speed were selected to study on technological characteristics. The tool electrode selected was a copper-tungsten (25% copper and 75% tungsten by weight) cylindrical rod with a central hole for efficient flushing. The experiments were designed using central composite design (CCD) procedure. Through holes of 25 mm depth were drilled in all the experiments. The output responses measured were material removal rate (MRR), relative wear ratio (RWR) and depth averaged surface roughness (DASR). The significant operating parameters influencing MRR, RWR and DASR were identified at 5% level of significance. The parameters peak current and electrode speed are more significant on MRR and RWR, whereas peak current and pulse on-time are highly significant on DASR.

Keywords: central composite design; CCD; copper; tungsten; Cu-W; deep hole drilling; electrical discharge machining; EDM; Inconel 718; electro-discharge machining; material removal rate; MRR; relative wear ratio; surface roughness; surface quality.

DOI: 10.1504/IJMMS.2012.049969

International Journal of Mechatronics and Manufacturing Systems, 2012 Vol.5 No.5/6, pp.399 - 418

Received: 04 Aug 2011
Accepted: 22 Jan 2012

Published online: 21 Aug 2014 *

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