Experimental and Digimat-FE based representative volume element analysis of exceptional graphene flakes/aluminium alloy nanocomposite characteristics

Abstract

The present article is focused on the in-house synthesis of graphene nano-flakes (size range: 3-8 nm) reinforced Al-alloy (AA6005 series) nanocomposites using stir casting process. The microstructure of the obtained Al nanocomposites at different concentration of flake shaped graphene nanoparticles (GRNPs) show that the particles at 2 wt% and 4 wt% found to be distributed extensively on the surfaces of Al alloy matrix but observed negligible across the grain boundary whereas in the case of 6 wt% concentrated developed composite specimen, the GRNPs were observed to be well dispersed both on the surfaces and grain boundary of the matrix. With the addition of the particles, there found to be the formation of more voids in the nanocomposite specimens. The experimental characterization results reveal that with the increase in graphene content to 6 wt%, the tensile strength, compressive strength, impact energy, hardness and wear resistance of the nanocomposites were increased by 9% to 36%, 30% to 44%, 9.8 J, 36.03 HRB and 33% respectively as compared to unreinforced alloy. It was observed that the composites with increased concentration of reinforcement exhibits brittle behaviour and at 6 wt% GRNPs, the elongation is almost found to be 50% lower than the unreinforced one. Further, a 3D microstructure representative volume element (RVE) model of aluminium nanocomposite is generated using Digimat-FE software. Then, microstructural deformation behaviour of the nanocomposite is realized by RVE model. The simulation results reveal that the tensile property of the aluminium nanocomposites predicted using RVE model is in well agreement with the experimental values. 2019 IOP Publishing Ltd.