Surface modification of aluminium and its parametric optimization using grey relational analysis

Abstract

This paper describes about the surface modification of aluminium workpiece using tungsten- copper (W-C) powder metallurgical (PM) green compact tool in electro discharge machining (EDM) process. Total nine experiments were conducted based on Taguchi L9 orthogonal array. The major response parameters selected were material transfer rate (MTR), tool wear rate (TWR) and surface roughness (Ra). The corresponding machining parameters were compaction load, peak current and pulse on-time. The experimental results were treated with grey relational analysis (GRA) for multi objective optimization. The highest grey relational grade (Gi) value was found to be 0.79 at the optimal parameter setting of 5 ton of compact load, 4 A of current and 400 µs of pulse on-time. ANOVA for grey relational grade was performed to investigate the effect of relevant process parameters in multi response criteria. The pulse on-time was found to be most influencing parameter having 49.77% of contribution followed by peak current and compact load of percentage 24.95% and 16.27% respectively.