Atomic-scale study of lattice distortion and oxygen-rich environment impact on the surface degradation dynamics of zinc-based alloys

Abstract

Mechanical stress and environmental conditions are main factors affecting the corrosion process of Zn-based alloys. In this work, density functional theory-based simulations are utilized to study the atomic-scale mechanism of degradation of the Zn-based alloys surface. Our findings suggest that lattice distortion promotes surface degradation of Zn-based alloys by increasing their surface reactivity and reducing work function, thus, decreasing O₂ adsorption energy. Oxygen adsorption on Zn surface can lead to the formation of a local dipole, which increases the work function of the surface. Notably, at a specific tensile strain of 1.5 % a reorientation of a local dipole induces an increase of the O₂ adsorption energy. These results highlight the significant impact of lattice distortion and the O₂ adsorption on the degradation dynamics of Zn-based alloys, offering valuable insights for the design of advanced biodegradable Zn-based alloys.