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The interfacial properties of graphene/Al composites are of critical important for exploring its high mechanical performance. To improve the mechanical properties, many experimental works have been done in past decades, however, the understanding of their physical mechanisms are limited. Here, the electronic structures and interfacial adhesion properties of pristine/virous deficient graphene(0 0 1)/Al(1 1 1) interfaces are calculated by first-principles method. Results show that single vacancy defective graphene (SVG)/Al interface has larger work of adhesion (Wad) of 5.62 J/m2 than the pristine (Wad of 1.03 J/m2) and other defective graphene/Al interfaces (Wad of 5.12 J/m2 for boron doped single vacancy defective graphene (BVG)/Al and Wad of 5.12 J/m2 for double vacancy defective graphene (DVG)/Al, respectively) due to the strong hybridization of Al-2p and C-2p orbits, which giving rise to the formation of polar covalent bonds with the bond populations of 0.62–0.72 at the deficient site The corresponding interface spacing decreasing from 2.72 A (Pristine Gra/Al) to 2.17 A (SVG/Al). And the defective graphene doped by B atoms could inhibit the interaction between Al and C atoms in the BVG/Al interface. Comparing with the SVG and BVG cases, the interface interaction strength of DVG/Al interface decreases due to the formation of octatomic ring, which could cape the carbon dangling bond and lead to a small structure deformation of graphene. However, it maintains a high Wad of 3.98 J/m2, indicating a better interface bonding strength than idea Gra/Al.

Bridging both the edges and the center of multicomponent space, which have been widely investigated in traditional alloys and high entropy alloys respectively, is significant but difficult in the design of alloys. In this paper, the single-crystal elastic constant model of the quaternary BCC Nb-Ti-V-Zr system across full composition space was established using first principles combined with the CALPHAD model. The accuracy of the model was confirmed by comparing with previous calculations and experiments. Using the fitted model, the alloying effect on stability and polycrystalline elastic properties of the current research system was analyzed. We find that there exists an area where BCC becomes unstable, and all the instability is caused by breaking C11-C12 > 0. And all of the stable Nb-Ti-V-Zr is ductile. In addition, there lies a surface on which the alloys are completely isotropic in elasticity. Furthermore, some alloys promising in some special aspects are predicted, such as gum metal, directional auxetic properties and biomedical application materials.