Corrosion resistance of ZrO₂–Zr-coated biodegradable surgical magnesium alloy

Abstract

Magnesium alloys are potential biodegradable biomaterials in hard tissue implants. However, the fast degradation rate in the biological environment has hampered widespread applications. We propose to use a ZrO 2 coating in conjunction with a Zr transition layer to improve the corrosion resistance of AZ91 magnesium alloy. X-ray photoelectron spectroscopy discloses that the coating is composed of ZrO 2 . The Vickers hardness measurement demonstrates that the surface hardness of the alloy is significantly enhanced. The electrochemical behavior of the coated sample is systematically evaluated by means of potentiodynamic polarization, open-circuit potential evolution, and electrochemical impedance spectroscopy. The electrochemical results indicate that the corrosion resistance of the coated alloy is enhanced significantly, and the electrode-controlled processes in a coated alloy-solution system are discussed.

Evaluation of corrosion resistance and cytocompatibility of graded metal carbon film on Ti and NiTi prepared by hybrid cathodic arc/glow discharge plasma-assisted chemical vapor deposition

“…Here, n P , n IL , and n OL are indices of the dispersion effect of the CPE components representing their deviations from the ideal capacitance due to surface roughness and inhomogeneity of the electrode on the micro-scale. The values of n P , n IL , and n OL are always between 0 and 1 [72] and are in this range in this study. The untreated Ti has an n P of 0.85 ± 0.01 whereas G1 shows an n P of 0.83 ± 0.12 along with n IL of 0.77 ± 0.09 and n OL of 0.81 ± 0.19 ( Table 2).…”

Microstructure and in vitro degradation performance of Mg–Zn–Mn alloys for biomedical application

“…An additional constant phase element, CPE f , and a resistance, R f , were also introduced to account for the capacitance and resistance of the corrosion product layer formed at the surface of Mg–Zn–Mn alloys. Xin et al29, 30 and Song et al31 have used a similar model to explain the corrosion behavior of Mg–Al–Zn alloys in simulated body fluids. The validity of the model is confirmed by the better nonlinear least square fitting of the experimental data within 5% error.…”

Surface treatments for controlling corrosion rate of biodegradable Mg and Mg-based alloy implants

“… (a) Cross-section morphology of TiO 2 coated AZ31 substrate and its potentio-dynamic polarization curve with respect to the uncoated substrate (reproduced from [ 59 ] under a Creative Commons Attribution License), (b) corrosion rate and cell viability of CaMgSi 2 O 6 diopside coating along with uncoated and micro-arc oxidation (MAO) coated AZ91 substrate (reprinted from [ 60 ], copyright 2014, with permission from Elsevier), (c) cross-sectional morphology and potentio-dynamic polarization curves of Zr/ZrO 2 coated AZ91 substrate (reproduced from [ 61 ], copyright 2011 Cambridge University Press), (d) scanning electron microscopy (SEM) images of morphologies of CaP + silicate coated AZ31 and Mg-4Y alloys immersed in polymyxin B1 (PB1), polymyxin B2 (PB2), and polymyxin B3 (PB3) after 3 days of culture (reprinted from [ 62 ], copyright 2011, with permission from Elsevier). …”