Graphene-reinforced aluminum-matrix composites (AMC) are superior to various Cu-matrix composites and aluminum alloys in automotive and aerospace applications, as they not only exhibit high strength and high conductivity but meet the demands of being lightweight and low-cost as well.
We did a study on the effect of graphene sheets on the mechanical and electronic properties of Al/G composites, using a superlattice (SL) model.
In Fig. 1, the bigger circles in blue represent aluminum atoms, the smaller circles in brown represent carbon atoms and the dash-lines indicate the unit cell of the superlattice.
Our calculations show that the binding between Al and graphene layers with no new chemical bonding at the interface is weak, and the binding strength gradually decreases as graphene content increases.
We determined the elastic constants using stress-strain approach.
The elastic moduli such as volume (B), shear (G) and Young's modulus (E) were found to increase quadratically with the graphene content.
Assuming one-dimensional rectangular potential barrier is 8eV high and 1.8Å wide, taken from the planar average electrostatic potential, the transmission probability was calculated to be 37%.
We confirmed that the mechanical strength of Al/graphene composites increases when graphene layers are inserted, and the critical value of graphene content to maintain ductility is 14.7%.
The research results have been published in the Journal of Applied Physics Letters under the title of "Influence of interposed graphene sheets on mechanical and electronic properties of Al/graphene superlattice" (https://doi.org/10.1063/5.0184043).
