Elastic Modulus Prediction of Graphene Nano-platelets Aluminum Nano-Composite by MD Simulations and Experiments

In this paper, molecular dynamics simulations of a representative volume element (RVE) of aluminum graphene reinforced nanocomposites have prepared. The effect of different weight percentages of graphene on nanocomposite Young’s modulus for armchair and zigzag directions were studied using an open source atomic simulator LAMMPS. The outputs were compared with the well-known rule of mixtures (ROM) technique, which has revealed that ROM can provide a reasonable estimate for less than 1wt.% of graphene. Besides, experimental investigations were conducted based on flake powder metallurgy to mechanically characterize the fabricated nanocomposite sample. The composite powder was first ball milled, then compressed to form a disk and finally, the raw body was sintered in a furnace. The two-step ball mill technique was performed to maximize graphene distribution which was confirmed by implemented detectors. The elastic modulus of the nanocomposite sample was determined using nano-indentation and dynamic mechanical analyzer while the morphology, microstructures, and distribution of graphene and aluminum powders were examined with SEM, FESEM and Raman spectrum. The final results were compared which have shown the positive effect of graphene nano-platelets as the reinforcement in both micro and macro-mechanics.