In Situ Synchrotron X‐Ray Diffraction Characterization of Corrosion Products of a Ti‐Based Metallic Glass for Implant Applications

Abstract

Ti-based bulk metallic glasses are under consideration for implants due to their high yield strength and biocompatibility. In this work, in situ synchrotron X-ray diffraction (XRD) is used to investigate the corrosion products formed from corrosion of Ti Zr Cu Pd Sn bulk metallic glass in artificial corrosion pits in physiological saline (NaCl). It is found that Pd nanoparticles form in the interior of the pits during electrochemical dissolution. At a low pit growth potential, the change in lattice parameter of the Pd nanoparticles is consistent with the formation of palladium hydride. In addition, a salt layer very close to the dissolving interface is found to contain CuCl, PdCl , ZrOCl ∙8H O, Cu, Cu O, and several unidentified phases. The formation of Pd nanoparticles (16 ± 10 nm at 0.7 V vs Ag/AgCl) containing small amounts of the other alloying elements is confirmed by transmission electron microscopy. The addition of albumin and/or H O does not significantly influence the nature of the corrosion products. When considering the biological compatibility of the alloy, the biological reactivity of the corrosion products identified should be explored.

Review on Biocompatibility and Prospect Biomedical Applications of Novel Functional Metallic Glasses

“…In the described alloys, potentially problematic in long-term use or more corrosive environments, can be the presence of Cu and Pd. The latter, even though bio-friendly, can cause the formation of Pd nanoparticles during the pitting corrosion of TiZrCuPd metallic glasses [ 162 ] leading to cytotoxic effects [ 163 ].…”

The Influence of Partial Replacement of Cu with Ga on the Corrosion Behavior of Ti40Zr10Cu36Pd14 Metallic Glasses

“…This is likely to be because Cu and Ga have similar anodic reactivity at the pitting potentials of the metallic glasses (Figure 8). The susceptibility to pitting is likely to be associated with the dissolution of Cu, Ga and Zr since Gostin et al found that metallic Pd is enriched in pits in a similar metallic glass 13 whereas Ti is highly resistant to pitting, 22,23 and pure Zr is susceptible to pitting at the potentials indicated in this work. 24 Corrosion behavior of as-spun ribbon and as-cast rod.-The specimens fabricated as ribbons and rods were produced from the same alloy, and neither showed crystalline peaks following XRD characterization.…”

“…SEM imaging of the pit morphology revealed a large accumulation of corrosion products at the pit surface which were demonstrated using EDX spectroscopy to be enriched with Pd and Cu. 12,13 The addition of a minor alloying element such as 1 at.% Nb or Ta to this alloy system has been shown to reduce the passive current and increase the pitting potential. 14 Melt spinning and mould casting are the two main fabrication methods used to produce metallic glasses.…”

Surface Chemistry Dictates the Osteogenic and Antimicrobial Properties of Palladium‐, Platinum‐, and Titanium‐Based Bulk Metallic Glasses

“…The growth of the oxide phase and concurrent shrinkage of Pd, Cu regions during aging suggest that these elements are likely released during the aging process in a manner similar to a process previously observed by in situ synchrotron XRD. [ 51 ] In contrast, Ti64 shows the most significant changes during the aging process with a growth of up to 120 nm‐long TiO needles (Figure 5D).…”