Synergistic effect of solute and strain on the electrochemical degradation in representative Zn-based and Mg-based alloys

Abstract

Using density functional theory and an improved Butler-Volmer model, we comparatively investigate the underlining mechanisms of solute alloying and mechanical straining on the electrochemical polarization and degradation behaviors of both Mg-based and Zn-based alloys. Our results suggest that some elements such as Li can potentially decrease the degradation rates for both alloys, while others like Fe, Ni, Cu, and Al, will play an opposite effect. By introducing the scaled strain energy to study the strain effect on the degradation kinetics of both alloys, we further reveal that both tensile and compressive strain would promote the degradation rate by decreasing the activation energy barrier.