Parametric optimisation of electric discharge coating process with powder metallurgy tools using Taguchi analysis

Abstract

From the last decade the electrical discharge machining (EDM) has been investigated as the process for surface modification besides machining. This paper describes the influence of W–Cu powder metallurgical electrodes at various parametric conditions on the surface of mild steel through electric discharge coating (EDC) process for its modification. Taguchi design of experiments is used to investigate the parameters which favour material transfer rate (MTR) with acceptable surface finish. Analysis of variance (ANOVA) and overall evaluation criteria (OEC) has been performed to the output parameters such as MTR and surface roughness R_a to find the percentage contribution of different controlling parameters for uniform deposition. The highest MTR of 195 mg min⁻¹ and the surface roughness of 2·6 μm have been successfully achieved.

Keywords:

• EDM
• EDC
• Powder metallurgy
• Surface
• Integrity
• Modification
• Taguchi

This experimental work is a part of RPS project of All India Council for Technical Education (AICTE) titled ‘Experimental Investigation of Surface integrity in Electrodischarge machining (EDM)’. The authors are very much thankful to the sanctioning authority of AICTE of India. The authors are also thankful to the Department of Mechanical Engineering, specially Dr P. Saha, Associate Professor, Department of Mechanical Engineering of IIT Kharagpur and Central Research Facility (CRF) of IIT Kharagpur, India for extending the facilities for characterization of the samples.