Micro Electro Discharge Machining of CNT-Based Nanocomposite Materials

Abstract

Since the discovery of carbon nanotubes (CNTs), there has been great interest in CNT-based composites. Well-developed micromachining processes are necessary to realize micron-size CNT-based composite products. Micro electro discharge machining (micro-EDM) has been applied into many challenge-to-cut materials such as ceramic composites. In this study, micro-EDM is used to machine CNT-reinforced polymer composites in the micro scale. CNT-based polymer composites were fabricated using solution casting, in which CNTs were dispersed in the polymer-solvent solution via high energy sonication, followed by precipitation and hot pressing. The investigation uses design of experiments (DOE) approach to screen of influential input factors for process measures. A 2 level fractional factorial design was used with four input factors; CNT loading on the workpiece, mu-EDM supply voltage, pulse on-time duration, and pulse on-time ratio. With 16 mu-EDM experiments, supply voltage was found to be most influential to the material-removal-rate (MRR). Scanning electron microscope (SEM) was used to investigate characteristics of the machined CNT-based nanocomposite surfaces.