Corrosion Behavior of Mg-xGd-1Zn-0.4Zr Alloys with Different Gd Additions for Biomedical Application

Abstract

In recent years, Mg alloys have attracted increased attention for biomedical application owing to their good biodegradability, biocompatibility, and biomechanical properties. However, rapid corrosion is still one of the most common limitations for their implanted application. In this work, the microstructure and corrosion behavior of the solution- and aging-treated Mg-xGd-1Zn-0.4Zr (x = 3, 6, and 9 wt%, denoted as GZ31K, GZ61K, and GZ91K, respectively) alloys were studied using optical microscope (OM), scanning electron microscope (SEM), immersion tests, electrochemical tests, and quasi in situ corrosion method. The results show that block Gd-rich precipitates and needle-like Zr-Zn-rich precipitates are formed as well as α-Mg matrix. With the increase in Gd content, the precipitates increase and the grain size first reduces and then increases. Corrosion experiment results show that the GZ61K alloy has the best corrosion resistance and the GZ91K alloy shows the highest corrosion rate among the three alloys in simulated body fluid (SBF). It is found that α-Mg is preferentially corroded and the precipitates have better corrosion resistance as compared to the α-Mg matrix. The GZ61K alloy with the corrosion rate of 0.227 mm/y in SBF shows a promising prospect for biomedical application.

Improved Corrosion Properties of Mg-Gd-Zn-Zr Alloy by Micro-Arc Oxidation

“…The corrosion electrochemical behaviors of the samples in simulated body fluid (SBF; the compositions are listed in Table 1 [22]) was measured on a standard three-electrode system electrochemical workstation (PARSTAT2273, Ametek Company, Berwyn, PA, USA), in which the uncoated or coated Mg alloy with an exposed surface area of 1 cm 2 was used as working electrode, platinum electrode as auxiliary electrode, and saturated calomel electrode as the reference electrode. Electrochemical impedance spectrum (EIS) and polarization tests were conducted.…”

Metals Biotribology and Oral Microbiota Biocorrosion Mechanisms

“…It increases the mechanical and corrosion resistance of the alloy, which is why it is used in dental materials [ 43 , 44 ]. The Mg-Li alloys as bioabsorbable dental implants have shown in vitro that the biodegradation and absorbability times of the alloys are equivalent to those required for bone regeneration [ 45 ].…”