Strong bonding effect and Zn segregation et Al/Fe bimetallic composite interface: A first-principles study

The focus of this first-principles study is to elucidate the interface structure and interactions at the Al/Fe bimetal interface by comparing the interfacial properties with and without Zinc segregation. First, the interface between Al and Fe was evaluated by atomic structure and energy, which includes different terminals. Next, by comparing the charge density difference and the electronic density of states of different models, we found that the Al(110)/Fe(110) OT configuration of the relaxation process transforms into the heterogeneous Al(110)/Fe(110) HCP configuration and exhibits the strongest covalent bonding features. Finally, we investigated the effect of zinc on interfacial stability and bonding. The segregation of zinc at the interface leads to interfacial embrittlement and weakened adhesion. The brittleness is stronger when the segregation site is located at the iron surface and the interfacial gap. The relationship between interfacial adhesion and segregation energy is quasi-linear. Graphical abstract