The Influence of MgH2 on the Assessment of Electrochemical Data to Predict the Degradation Rate of Mg and Mg Alloys

International Journal of Molecular Sciences

Wolf-Dieter Mueller¹ 

[1] Biomaterial Research CC3, Dental School Charité Universitaetsmedizin Berlin, Assmannshauserstrasse 4-6, Berlin 14197, Germany

关键词: magnesium;    magnesium alloys;    magnesium hydride;    corrosion;    degradation;   

DOI  :  10.3390/ijms150711456

来源: mdpi

【 摘 要 】

Mg and Mg alloys are becoming more and more of interest for several applications. In the case of biomaterial applications, a special interest exists due to the fact that a predictable degradation should be given. Various investigations were made to characterize and predict the corrosion behavior in vitro and in vivo. Mostly, the simple oxidation of Mg to Mg²⁺ ions connected with adequate hydrogen development is assumed, and the negative difference effect (NDE) is attributed to various mechanisms and electrochemical results. The aim of this paper is to compare the different views on the corrosion pathway of Mg or Mg alloys and to present a neglected pathway based on thermodynamic data as a guideline for possible reactions combined with experimental observations of a delay of visible hydrogen evolution during cyclic voltammetry. Various reaction pathways are considered and discussed to explain these results, like the stability of the Mg⁺ intermediate state, the stability of MgH₂ and the role of hydrogen overpotential. Finally, the impact of MgH₂ formation is shown as an appropriate base for the prediction of the degradation behavior and calculation of the corrosion rate of Mg and Mg alloys.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.