In vitro corrosion behaviour of Mg alloys in a phosphate buffered solution for bone implant application

Abstract

The corrosion behaviour of Mg-Mn and Mg-Mn-Zn magnesium alloy in a phosphate buffered simulated body fluid (SBF) has been investigated by electrochemical testing and weight loss experiment for bone implant application. Long passivation stage and noble breakdown potential in the polarization curves indicated that a passive layer could be rapidly formed on the surface of magnesium alloy in the phosphate buffered SBF, which in turn can protect magnesium from fast corrosion. Surfaces of the immersed magnesium alloy were characterized by SEM, EDS, SAXS and XPS. Results have shown that Mg-Mn and Mg-Mn-Zn alloy were covered completely by an amorphous Mg-containing phosphate reaction layer after 24 h immersion. The corrosion behaviour of magnesium alloys can be described by the dissolving of magnesium through the reaction between magnesium and solution and the precipitating of Mg-containing phosphate on the magnesium surface. Weight loss rate and weight gain rate results have indicated that magnesium alloys were corroded seriously at the first 48 h while Mg-containing phosphate precipitated fast on the surface of magnesium alloy. After 48-96 h immersion, the corrosion reaction and the precipitation reaction reach a stable stage, displaying that the phosphate layer on magnesium surface, especially Zn-containing phosphate layer could provide effective protection for magnesium alloy.

In vitro degradation and biocompatibility of Mg-Nd-Zn-Zr alloy

“…Zinc is a common alloying element in magnesium, and helps overcome the harmful corrosive effect of impurities such as iron and nickel, thus improving the corrosion resistance of magnesium alloys [27]. Xu et al [28] also proposed that the addition of zinc into magnesium could improve the corrosion resistance. Zirconium is usually used as a grain refiner in magnesium alloys without aluminum, thereby contributing to the strength of these alloys and reducing the adverse effects of iron contaminants on the corrosion resistance of magnesium alloys [29,30].…”

In vivo degradation behavior and biocompatibility of Mg-Nd-Zn-Zr alloy at early stage

“…Zinc is a common alloying element added in magnesium and its strengthening effect is second only to aluminum (21). Xu et al (13) proposed that the addition of zinc in magnesium could improve the corrosion resistance. Zirconium is usually used as a grain refiner in magnesium alloys, thereby contributing to the strength of these alloys (22).…”

“…Previous studies have confirmed that magnesium alloys have good biocompatibility, may promote osteocyte growth and may induce production of osteoblasts and osteocytes (11)(12)(13)(14)(15). Owing to suitable mechanical property and good biocompatibility, high specific strength and specific stiffness, degradable magnesium alloys can be utilized in many aspects such as bone repair material, coronary artery stent and porous repair material.…”

Introductory Chapter: Multi-Aspect Bibliographic Analysis of the Synergy of Technical, Biological and Medical Sciences Concerning Materials and Technologies Used for Medical and Dental Implantable Devices

“…The use of Mn, as a component of Mg alloys, consists of the improvement of corrosion resistance and may increase the plasticity of Mg alloys [383,399]. Zn improves the strength of Mg alloys [399,400] and their corrosive resistance [401]. However, its influence on increased cytotoxicity was identified [402,403].…”