Characterization and micro end milling of graphene nano platelet and carbon nanotube filled nanocomposites

Abstract

Graphene and carbon nanotubes (CNTs) have been used in polymeric nanocomposites for improved mechanical, electrical, thermal and gas barrier properties. As the major applications of these relatively new materials are expected to be in the micro/meso-scale, their micro-machinability needs to be investigated. In this study, graphene nano platelet (GNP) and multi-walled carbon nanotube (MWCNT) filled polycarbonate (PC) nanocomposites were fabricated through injection molding. The molded nanocomposites were characterized for their thermal and mechanical properties. Micro mechanical machining was performed on the molded specimens to understand the material removal behavior. The micro cutting forces were measured and compared for the fabricated GNP and MWCNT filled nanocomposites. The experimental results showed that the GNP filled PC nanocomposites required higher cutting forces than plain PC. The chip morphologies of the materials were explored under scanning electron microscopy. Finite element (FE) model of machining PC and PC-GNP nanocomposites was developed to determine the fundamental mechanisms of chip formation and surface generation due to the inclusion of the GNP fillers. The FE model was validated by the comparison of simulated and experimental micro milling forces. The results of this study show that the addition of GNP and MWCNT can significantly improve the dimensional accuracy and the quality of the machined surfaces.