Title: Parametric study of relative erosion of cathode and anode of SAE L7 low alloy tool steel in EDM using grey relational concept in L9 orthogonal array

Authors: Deepak Kumar Panda

Addresses: Defence R&D Organization, Govt. of India, Institute of Technology Management, Landour Cantt., Mussoorie, Pin-248179, India

Abstract: In EDM, dissimilar erosion of anode and cathode occur due to the effect of polarity even if both the electrodes interface each other under similar working condition and EDM process parameters. Dissimilar erosion is due to the difference in governing physical process associated with anode and cathode, unequal spatial source of heat that develops at both ends of electrodes, and unequal energy sharing. In this context, dielectric and thermo-physical properties of electrode material act as the concomitant parameters. Since dielectric is common in interfacing both the electrodes, considering common electrode material for both anode and cathode of SAE L7 low alloy tool steel, in the present paper, an experimental investigation based on L9 orthogonal array has been done to characterise spark-eroded craters formed on both anode and cathode surfaces. Due to the stochastic nature of machining, the observations of crater morphology fail to provide complete information regarding the parametric effects. Hence, grey relational analysis has been used to establish the significance of the process parameters based on Fisher test of grey relational coefficients. Finally, confirmatory experiments have been done to understand the nature of the relative erosion of anode and cathode with respect to EDM process parameters.

Keywords: anode erosion; cathode erosion; Fisher test; grey relational analysis; orthogonal arrays; low alloy tool steel; EDM; electro-discharge machining; electrical discharge machining; dissimilar erosion; spark-eroded craters; process parameters.

DOI: 10.1504/IJMMM.2010.033067

International Journal of Machining and Machinability of Materials, 2010 Vol.7 No.3/4, pp.208 - 229

Published online: 07 May 2010 *

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