Corrosion and electrochemical behavior of Mg-Y alloys in 3.5% NaCl solution
(1. State Key Laboratory for Fabrication and Processing of Nonferrous Metals,Beijing General Research Institute for Nonferrous Metals, Beijing 100088, China;2. Beijing Engineering Research Center for Advanced Manufacturing and Evaluation of Special Vehicle Parts,Beijing 100072, China;3. Technology Institute, Beijing North Vehicle Group Corporation, Beijing 100072, China)
Abstract: The corrosion mechanism of Mg-Y alloys in 3.5% NaCl solution was investigated by electrochemical testing and SEM observation. The electrochemical results indicated that the corrosion potential of Mg-Y alloys in 3.5% NaCl solution increased with the increase of Y addition. The corrosion rate increased with the increase of Y addition because of the increase of Mg24Y5 intermetallic amounts. The corrosion gradually deteriorated with the increase of immersion time. The corrosion morphologies of the alloys were general corrosion for Mg-0.25Y and pitting corrosion for Mg-8Y and Mg-15Y, respectively. The main solid corrosion products were Mg(OH)2 and Mg2(OH)3C1·4H2O.
Key words: Mg-Y alloy; polarization curves; pitting corrosion; corrosion products