Effect of Surface Mechanical Attrition Treatment (SMAT) on the Surface and Electrochemical Characteristics of Pb-Sn Alloy

Abstract

The influence of surface mechanical attrition treatment (SMAT) on the mechanical and electrochemical properties of Pb-Sn alloys is presented. SMAT induced plastic deformation of the Pb-Sn alloy to a depth of similar to 43 mu m from the top surface and enabled the formation of a graded layer structure. In spite the increase in average surface roughness (R-a) from 0.40 to 2.42 mu m, the uniform dimple-like features generated on the surface of the Pb-Sn alloy helped to improve the interfacial characteristics of active material and grid. SMAT has also enabled a marginal increase in hardness of the Pb-Sn alloy. The electrochemical behavior of the Pb-Sn and treated alloy was evaluated by employing potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The ability of the treated surface to induce passivation offered an increase in corrosion resistance. The current density of the redox reaction profile suggests good charge-discharge characteristics of the SMATed Pb-Sn alloy