Enhanced corrosion resistance of harmonic structured β-type Ti-25Nb-25Zr alloy in aerated Fusayama-Meyer’s simulated saliva solution

• Published in: Materials letters 2024-12, Vol.377, p.137409, Article 137409
• Main Authors: Banik, D., Baditela, Teja Sri, Mandal, Saikat, Fujiwara, H., Ameyama, K., Mondal, K.
• Format: Article
• Language: English
• Subjects: Corrosion; Electron backscatter diffraction; Harmonic structure; Microstructure; Ti-Zr-Nb alloy
• ISSN: 0167-577X
• DOI: 10.1016/j.matlet.2024.137409

[Display omitted] •A bimodal harmonic structure is generated in the β-type Ti-25Nb-25Zr alloy.•The harmonic structure in this alloy significantly improves corrosion resistance.•A higher fraction of high-angle grain boundary is attributed to the improvement. In this study, the microstructure of the β-type Ti-25Nb-25Zr alloy is modified to a bimodal harmonic design, exhibiting fine and coarse grains of ∼3 μm and ∼70 μm, respectively. The high-angle grain boundary density of the harmonic Ti-25Nb-25Zr alloy increases nearly fourfold over its coarse-grained counterpart. Both the harmonic and course-grained Ti-25Nb-25Zr alloys show excellent passivation and corrosion resistance when studied electrochemically in Fusayama-Meyer’s simulated saliva solution. The harmonic structure in the Ti-25Nb-25Zr further improves corrosion resistance, almost six times the coarse-grained counterpart. The improved corrosion resistance is attributed to the excessive high-angle grain boundary, which binds the corrosion product to the substrate, restricting further corrosion.