Characterization and energy calculation of the S/Al interface of Al–Cu–Mg alloys: Experimental and first-principles calculations

Abstract

In this work, the S/Al interface properties are investigated by aberration-corrected HAADF-STEM observations and first-principles calculations. Four interface atomic model is built from the images observed by transmission electron microscopy and the interfacial energy, adhesion work and electronic properties of the four interfaces are calculated. The calculations results demonstrate that the CuMg-terminated interface has the lowest interfacial energy and the highest adhesion work when compared to the other three interfaces. Among the candidate interfaces, the CuMg-terminated S(021)/Al(014) interface is the most stable in thermodynamics. By analyzing the density of states and charge density difference of the interface, it is found that strong Al–Cu covalent bonds are formed at the interface, making the S precipitated phase and Al matrix interface combination is more stable. Furthermore, energy calculations are applied to explain the rearrangement phenomenon of Cu atoms in the Z-contrast images of the experiment. Meanwhile, the fundamental data in this paper will be useful for comprehending various behaviors of the S/Al interfaces.