Interface optimization strategy for enhancing the mechanical and thermal properties of aligned graphene/Al composite

In the present work, we firstly used the first-principles calculation and molecular dynamics (MD) simulation to predict the graphene/Al interfacial properties, and it is found that graphene defect and Al alloying Cu(Mg) could be an effective method for enhancing the graphene/Al interfacial bonding strength and thermal conductance due to the pronounced hybridization and phonon-phonon coupling effect between interfacial Cu(Mg) atoms and C atoms near the vacancy. Then we successfully prepared the aligned graphene/2024Al composite with the optimized interfacial microstructure by the method of powder metallurgy. The results showed that the tensile strength of 0.5 wt% graphene/2024Al composite could reach 325 MPa and is ~38.3% higher than that of the 2024Al matrix, while the plasticity keeps almost unchanged. The thermal conductivity of 0.5 wt% graphene/2024Al composite is 16.3% (10.9%) higher than 2024Al matrix along (or vertical to) the aligned direction of graphene.