Experimental investigation of multi-wall carbon nanotube added epoxy resin on the EDM performance of epoxy/carbon fiber/MWCNT hybrid composites

In this study, the effect of multi-wall carbon nanotube (MWCNT) on machining damages and material removal mechanisms in electro-discharge machining (EDM) of carbon fiber reinforced epoxy resin (CFRE) was evaluated. Field-emission scanning electron microscopy (FE-SEM) was used to investigate the machined surface morphology and elemental analysis. The effect of MWCNT content, pulse current, and pulse-on time was investigated on machining damages such as delamination, hole taper, and machining characteristics containing tool wear and material removal rate. The experimental tests were conducted according to the full-factorial design of the experiment. The FE-SEM images showed that decomposition and vaporization are dominant removal mechanisms. Elemental analysis clarified that burning is one of the removal mechanisms in EDM of CFRE. Based on the elemental analysis, the burning mechanism is reduced by incorporation of the MWCNT into epoxy resin. The results of EDM machining tests showed that as compared to CFRE, introducing MWCNT into epoxy resin in epoxy/carbon fiber/MWCNT hybrid composites improves material removal rate and decreases delamination factor and taper hole.