Corrosion behavior of Zr-14Nb-5Ta-1Mo alloy in simulated body fluid.

Metals that are used to reconstruct skeletal structures often interfere with magnetic resonance imaging (MRI) owing to differences in magnetic susceptibility; consequently, metals with lower magnetic susceptibilities need to be developed for use in implant devices. Herein, we investigated the corrosion properties of the Zr-14Nb-5Ta-1Mo alloy, which exhibits low magnetic susceptibility and excellent mechanical properties. The pitting potential of Zr-14Nb-5Ta-1Mo was higher than that of pure Zr. The passive current density of Zr-14Nb-5Ta-1Mo also higher than that of pure Zr, which is ascribable to slow reconstruction of the initial passive film associated with the presence of Nb and Ta. XPS revealed that the passive film is enriched with Nb and Ta. Therefore, while the Zr-14Nb-5Ta-1Mo alloy exhibited a high initial passive current density in simulated body fluid, it formed a stable passive film that suppressed localized corrosion. Zr-14Nb-5Ta-1Mo is therefore a prospective implant-material alloy candidate.