Publication :
Niobium addition improves the corrosion resistance of TiHfZrNbₓ high-entropy alloys in Hanks’ solution

En cours de chargement...
Vignette d'image
Date
2022-06-02
Auteurs
Fan, Xuesong
Sakidja, Ridwan
Liaw, P. K. (Peter K.)
Direction de publication
Direction de recherche
Titre de la revue
ISSN de la revue
Titre du volume
Éditeur
Amsterdam : Elsevier
Projets de recherche
Structures organisationnelles
Numéro de revue
Résumé
High-strength TiHfZrNbₓ high-entropy alloys could become the ideal materials for small-diameter endovascular stents once their corrosion resistance in the physiological milieu is confirmed. This work aims at evaluating the corrosion resistance of a TiHfZrNbₓ high-entropy-alloys family in Hanks’ solution at 37 °C and revealing the influence of niobium on the mechanisms of dissolution and passivation. The alloys were subjected to a series of static and dynamic electrochemical tests and surface characterization, employing the static/dynamic/cyclic polarizations, impedance spectroscopy, XPS, AFM, and SEM. Results confirm a higher corrosion resistance of the alloys compared to that of CP-Ti and Ti6Al4V. The addition of niobium considerably improves the microstructural homogeneity that ensures a low dissolution rate and a greater resistance of the film due to the lower concentration of point defects. The passive film behaves as an n-type semiconductor and is composed of a mixture of TiO₂, Nb₂O₅, ZrO₂, and HfO₂ oxides, with the presence of metallic hydroxides on the outermost layer. A detailed description of the niobium influence on the mechanisms of the dissolution and passivation is presented in this work.
Description
Revue
Electrochimica Acta, vol. 24, 140651 (2022)
DOI
10.1016/j.electacta.2022.140651
URL vers la version publiée
Mots-clés
Biomaterials , Corrosion-resistance , High-entropy alloys , Passive films
Citation
Type de document
article