MICRO ELECTRO DISCHARGE MACHINING OF POLYMETHYLMETHACRYLATE (PMMA)/MULTI-WALLED CARBON NANOTUBE (MWCNT) NANOCOMPOSITES

Abstract

This study investigated micro electro discharge machining (micro-EDM) of Polymethylmethacrylate (PMMA)/ Multi-Walled Carbon Nanotube (MWCNT) nanocomposites. PMMA/MWCNT nanocomposites were fabricated using solution casting, in which MWCNTs were dispersed in the polymer-solvent solution via high energy sonication, followed by precipitation and hot pressing. MWCNT loading was varied to investigate the effect of electrical conductivity of nanocomppsites on the machinability. Micron-size holes were created to study the material removal mechanism in micro-EDM. The electro discharge phenomena may occur between electrically conductive MWCNT and the tungsten electrode during the process. As a result, PMMA/MWCNT nanocomposite samples with 10 to 35 wt% MWNTs were able to be EDMed with proper machining conditions. It was observed that the material removal rate increases with increasing micro-EDM supply voltage and MWCNT loading on the material system. Both optical microscope and scanning electron microscope (SEM) were used to investigate the characteristics of the machined holes and nanocomposite surfaces.