Effect of alternating voltage treatment on corrosion resistance of AZ91D magnesium alloy

Abstract

Abstract AZ91D magnesium alloy was treated by the alternating voltage (AV) treatment technique. The optimal AV‐treatment parameters of the alloy were determined by orthogonal experiments. Polarization curve, electrochemical impedance spectroscopy (EIS), and scanning electrochemical microscopy (SECM) were used to understand the effect of AV‐treatment on the corrosion resistance of the alloy. AFM, contact angle, and XPS were employed to investigate further the influence of AV‐treatment on the properties of the surface film formed on the alloy after AV‐treatment. The results showed that a uniform and stable film was formed and the corrosion resistance of AZ91D magnesium alloy was significantly improved after AV‐treatment. This was caused by the noticeable change of the chemical structure and semi‐conducting properties of the surface film after AV‐treatment.