Effect of interfacial microstructure on the mechanical properties of GNPs/Al composites

The interfacial bonding affects the performance of Graphene/Al matrix composites significantly. However, the relationship between interfacial structure and mechanical properties has not been fully understood yet. In the present work, the GNPs/Al composites were prepared by pressure infiltration method, and the interface structure of Graphene-Al₂O₃–Al and graphene-(Al₄C₃, Al₂OC)–Al was prepared by addition of polydimethylsiloxane (PDMS) as process control agent (PCA). The tensile strength of the GNPs/Al composite material with Al₂O₃ interfacial bonding was 303 MPa, which was about 30% higher than that with Al₄C₃ and Al₂OC interface. Moreover, calculated by first-principle, it has been found that the interfacial shear strength of the graphene-Al₂O₃–Al interface (378 MPa) was much higher than that of graphene-Al (37 MPa), graphene-Al₄C₃ (83 MPa) and graphene-Al₂OC (66 MPa), which leads to the improved mechanical properties.