Interfacial properties and fracture behavior of the L12-Al3Sc||Al interface: Insights from a first-principles study

Abstract

Deeply investigating the characteristics of the L12-Al3Sc||Al interface is a good strategy for improving the ductility and strength of next-generation Al alloys. Herein, rigid and fully relaxed models of L12-Al3Sc||Al were studied through first-principles calculations work to reveal the interface strength and fracture behavior. Results show that the most stable interface exhibited the largest fracture energy of 2.324 J/m2 and the largest tensile stress of 15.302 GPa. The calculations for the fully relaxed stretching model show that Al exhibited better elongation. The analysis of the electronic structure indicates that a uniform distribution of electrons at the interface stabilizes the interface structure and improve the interfacial strength. The calculations on density of states reveal that considerable hybridization occurs among the interfacial Al 3s, Al 3p and Sc 3d orbitals, forming s–p–d hybrid orbits. The most stable interface contained low-energy-state electrons than high-energy-state electrons and exhibited the most uniform electron distribution, which are the key factors leading to interface stabilization and strengthening.