Corrosion behaviour of AZ31 magnesium alloy with different grain sizes in simulated biological fluids

The corrosion behaviour of AZ31 magnesium alloy with different grain sizes immersed in simulated body fluids was compared in chloride solution (8 g l−1) and in phosphate-buffer solution (PBS). The influence of immersion time was also analyzed. Electrochemical techniques such as open circuit potentia...

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Bibliographic Details
Authors: Álvarez-López, María, Pereda, M. D., Valle, Jorge del, Fernández Lorenzo, M., García-Alonso, M. C., Ruano, Oscar Antonio, Escudero Rincón, María Lorenza
Format: article
Publication Date:2010
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/59353
Online Access:http://hdl.handle.net/10261/59353
Access Level:Open access
Keyword:AZ31 Mg alloy
Grain size
Biomaterials
Corrosion
Electrochemical techniques
Description
Summary:The corrosion behaviour of AZ31 magnesium alloy with different grain sizes immersed in simulated body fluids was compared in chloride solution (8 g l−1) and in phosphate-buffer solution (PBS). The influence of immersion time was also analyzed. Electrochemical techniques such as open circuit potential, polarization curves, transient currents and electrochemical impedance spectroscopy, complemented with scanning electron microscopy and energy dispersive spectroscopy, were used. Immediately after the immersion in the corrosive media the corrosion resistance was similar for both grain sizes of the AZ31 alloy and higher in NaCl solutions than in PBS. However, this corrosion behaviour was reversed after longer periods of immersion due to the stabilizing of the corrosion products of MgO by P-containing compounds. These P-compounds contribute to a higher level of protection by hindering the aggressive action of chloride ions. The best corrosion behaviour of the AZ31 alloy was obtained for the finest grain alloy associated with the highest transfer resistance value, after long periods of immersion in PBS.