First-principles investigation on the tensile strength, interfacial stability and electronic structure of the heterogeneous nucleation Al/VB2 interfaces

Abstract

First principles calculations based on the density functional theory were performed on the interfacial properties of Al(111)/VB2(001) and Al(100)/VB2(100) interfaces including interfacial stability, bonding features and tensile strength. Fourteen different interfaces with different VB2 terminations (V-terminated and B-terminated) were studied. The convergence test shows that 7-layered Al(111) and 9-layered Al(001), 9-layered VB2(001) and 13-layered VB2 (100) are thick enough to build Al/VB2 interface. The (001)-V-hcp and (100)-V-cen site interface have the largest work of adhesion (Wad) among the Al(111)/VB2(001) and Al(100)/VB2(100) interfaces. And under V-rich condition, there interfacial energies are − 0.44 J/m2 and − 0.45 J/m2 which are much lower than 0.15 J/m2, indicating it is an effective heterogeneous nucleation substrate for α-Al. The main bonding characteristics is metallic for the (001)-V-hcp interface, while it is covalent with metallic for the (100)-V-cen interface, making it has the largest Wad. The calculated tensile strength of (001)-V-hcp site interface is about 7.36Gpa when the strain is 12 %. While it is 6.27Gpa for the (100)-V-cen site interface at 10 %. Finally, the VB2 particles are proved to be an effective heterogeneous nucleation substrate for α-Al as observed from experiment.