Microstructures and degradation mechanism in simulated body fluid of biomedical Mg–Zn–Ca alloy processed by high pressure torsion

In this paper the in vitro degradation of ultrafine grained (UFG) Mg-Zn-Ca alloy produced by HPT was investigated by electrochemical measurements and immersion tests in SBF. It was found that UFG Mg alloy had better degradation properties and also higher microhardness value than as-cast Mg alloy. The corrosion current density of UFG Mg alloy decreased by about two orders of magnitude, compared with that of as-cast alloy. Through electrochemical impedance spectroscopy (EIS) test，UFG Mg alloy showed a higher charge transfer resistance value. In immersion test, UFG Mg alloy in SBF exhibited more uniform corrosion and lower degradation rate (0.0763 mm/yr) than as-cast alloy. The degradation properties were related with the microstructure evolution, namely the grain refinement and redistribution of second phase. Keywords: Mg-Zn-Ca alloy; High-pressure torsion (HPT); Degradation behavior; Simulated body fluid (SBF); Microhardness

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Insight into the corrosion behaviour and degradation mechanism of pure zinc in simulated body fluid

Corrosion Science ◽

10.1016/j.corsci.2020.109071 ◽

2021 ◽

Vol 178 ◽

pp. 109071

Author(s):

Shiyu Huang ◽

Wei Wu ◽

Yanjing Su ◽

Lijie Qiao ◽

Yu Yan

Keyword(s):

Simulated Body Fluid ◽

Body Fluid ◽

Corrosion Behaviour ◽

Degradation Mechanism ◽

Pure Zinc ◽

Insight Into

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Calcium Titanate Film-Coating on Titanium with Hydrothermal Treatments

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.330-332.737 ◽

2007 ◽

Vol 330-332 ◽

pp. 737-740 ◽

Cited By ~ 2

Author(s):

Masayuki Kon ◽

Razia Sultana ◽

Emi Fujihara ◽

Kenzo Asaoka ◽

Tetsuo Ichikawa

Keyword(s):

High Pressure ◽

Surface Modification ◽

Simulated Body Fluid ◽

Body Fluid ◽

Titanium Surface ◽

Film Coating ◽

Calcium Titanate ◽

Maximal Pressure ◽

Titanium Surfaces ◽

Modification Of Titanium

Film-coating on the surface of titanium was investigated by hydrothermal treatments with a maximal pressure of 6.3 MPa (280°C) in CaO solution and water to improve bioactivity and biocompatibility. As a result, calcium titanate (CaTiO3) film was formed on the titanium surface. The surface-coated titanium was immersed in a simulated body fluid (SBF) to estimate its bioactivity. Apatite precipitation was observed on all hydrothermal-treated titanium surfaces after immersion in SBF for 4 weeks. In particular, the apatite precipitation of titanium treated with 6.3 MPa in CaO solution was clearer and larger in amount than those of all other hydrothermal-treated specimens. The results suggest that surface modification of titanium with high-pressure hydrothermal treatments can be expected to improve bioactivity and biocompatibility.

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