Finite element and experimental studies on the machining process of polymer/graphene nanoplatelet nanocomposites

Polymer matrix composites reinforced with graphene derivatives are receiving increasing attention in academia and industry. For future applications, however, the machinability of these materials needs to be understood. This study introduces the cutting mechanism of graphene nanoplatelet (GNP)-reinforced polymer matrix composites using the finite element (FE) method, where the cutting process is investigated in terms of stress distribution, chip formation, and surface morphology. The results show that the machined surface of polymer/GNP material has more defects compared with plain polymer and the presence of the GNPs influences the chip profiles. Small cavities/cracks can be found in about 40% area of machined surface in the epoxy/GNP, while no small cavities/cracks are found on the machined surface of plain epoxy. The machining conditions of epoxy/GNP should be selected in such a way that the material removal deformation falls in the regime without viscoplastic scaling/tearing and brittle cracking. The cutting model for polymer/GNP is validated with the machining experiments.