Response of surface mechanical properties to electrochemical dissolution determined by in situ nanoindentation technique

An in situ nanoindentation technique was used to study the mechanical property degradation in the surface layer induced by electrochemical dissolution. The load–depth curves of indentation were measured using pure iron immersed in electrolyte. The experimental result showed that the anodic currents reduced both hardness and elastic modulus of the material surface layer, and the degradation effect declined with increasing distance from the surface. The electrochemical dissolution-induced degradation was explained by the generation of non-equilibrium vacancies in the metal surface layer during dissolution process.