Investigation on surface Integrity, Machining and Form tolerance characteristics using TOPSIS approach for Electrical Discharge Machining of Biocompatible material

Abstract

Abstract Magnesium alloy (AZ91D) is a biocompatible material used for manufacturing critical degradable orthopaedic implants. One of the significant manufacturing processes used for machining these orthopaedic implants is Electric Discharge Machining (EDM). EDM is a non-traditional machining process where electric energy is used for removal of material from the work piece. The focus of this work is to optimize and investigate the contribution of process parameters such as discharge current (I), pule on time (TON), pulse off time (TOFF) on response variables such as surface roughness (Ra), material removal rate (MRR), tool wear rate (TWR), overcut (OC), tapercut (TC), circularity (CIR) and cylindricity (CYL). The experiments are carried out based on Taguchi’s L16 orthogonal array. The discharge current is found to contribute significantly on response variables when compared with other experimented process parameters. The performance measures are converted into equivalent single performance measure for achieving the required level of responses by calculating the relative closeness coefficient using the Techniques for Order Preferences by Similarity to Ideal Solution (TOPSIS) approach