Experimental investigation of MWCNTs mixed EDM of Ti-6Al-4V surface

Abstract

In the present study, Taguchi's methodology with L9 orthogonal array applied for the investigation of ED machined Ti-6Al-4V alloy viz. discharge current, pulse-on-time, pulse-off-time and voltage as input process parameters. MWCNTs mixed hydrocarbon oil used as dielectric medium to machine Ti-6Al-4V alloy using graphite electrode with reverse polarity. The output responses assessed as material erosion rate, electrode wear and surface integrity. The significance and contribution of input process parameters on the output responses analysed using analysis of variance. From the experimental results, discharge current evident significant factor for material erosion rate (contribution: 75.76%) and electrode wear rate (contribution: 77.55%). Whereas, pulse-on-time (contribution: 65.75%) followed by pulse-off-time (contribution: 28.18%) exhibits notable surface finish. Furthermore, a regression based model is developed and validated through a confirmative test. The micromechanics of the ED machined surface in terms changed morphology and phase transformation due to thermo process investigated using SEM and XRD analysis respectively. Keywords: powder mixed electrical discharge machining; PMEDM; material erosion rate; electrode wear rate; EWR; surface integrity; regression model. Reference to this paper should be made as follows: Bhui, A.S.