Evaluation of hole quality to explore the influence of graphene nanoplatelets embedded in epoxy/carbon composite during abrasive water jet drilling

Abstract

Carbon fibre reinforced polymer (CFRP) as a composite material has become an important subject for research with its increasing demand in the industrial sector. Machining of CFRP appears to be difficult owing to its heterogeneous and anisotropic nature. The present study has focused on the machinability of hybrid CFRP composites. During the investigations, the CFRP composites with 0 wt%, 0.125 wt%, 0.25 wt%, and 0.375 wt% of graphene nanoplatelets (GNPs) were fabricated using the hand layup technique. This study has attempted to explore the abrasive water jet (AWJ) drilling responses of the neat and the GNPs-embedded CFRP composites to assess their respective efficacy. The comparative study revealed that GNPs (0.25 wt%)-embedded CFRP improves flexural strength by 23.33% and interlaminar shear strength (ILSS) by 29.95% as compared to the neat CFRP. However, with GNPs above this quantity, the CFRP composite starts to lose these properties. During the investigation, while operating with the AWJ drilling parameters of high JP (400 MPa) and low TR (100 mm/min), the GNPs (0.25 wt%)-embedded CFRP was found to have lower Ra (1.3187 μm), KT (0.959°) as well as entry DF (1.0888), and exit DF (1.0655), respectively, compared to the neat CFRP. The JP was found to have a dominant impact concerning the Ra and KT, while GNPs content proved to have a greater influence concerning the entry and exit DF. The surface morphology of the drilled specimens revealed that surface defects developed more in the neat CFRP, which could be reduced by incorporating GNPs in the CFRP composite.