Corrosion of titanium, zirconium and their alloys for biomedical applications

Zhang, Yue (2018). Corrosion of titanium, zirconium and their alloys for biomedical applications. University of Birmingham. Ph.D.

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Abstract

in vivo degradation of Ti implants has remained as a concern despite its perceived excellent corrosion resistance. Elevated levels of metal have been detected both locally and systemically, often leading to unfavourable biological responses.
Corrosion of Ti, Zr and their alloys (Ti6Al4V and TiZr) were studied in simulated physiological solutions. It was found that albumin, the most prevalent tissue fluid protein, induced a time dependent dissolution of Ti6Al4V in the presence of H2O2, an inflammatory biomolecule commonly found in peri implant sites, in 0.9% NaCl. However, the corrosion of Zr was observed to be unaffected by the presence of H2O2 and/or albumin in 0.9% NaCl. Furthermore, TiZr alloys have been shown to possess enhanced passivity in comparison to CP Ti in the various exposure conditions including highly acidic (HCl), oxidative environments (H2O2 in 0.9% NaCl) and cell cultures (macrophage).
Corrosion products of Zr were characterised in situ by synchrotron X ray methods, which were found to be ZrOCl2 ∙ 8H2O, tetragonal ZrO2, and Zr metal fragments in 0.9% NaCl regardless of the presence or absence of H2O2 and/or albumin. The presence of Zr metal fragments as a result of a corrosion process indicates the generation of metal species in the absence of wear.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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