Influence of silver addition on microstructure and corrosion behavior of Mg–Nd–Zn–Zr alloys for biomedical application

• Micro-alloying element silver was added into biodegradable Mg–3.0Nd–0.2Zn–0.4Zr alloy.
• The microstructure was refined by Ag addition and the second phase became more continuous.
• The alloy with 0.2 wt% Ag showed the best corrosion resistance among Ag containing alloys.

Silver (Ag) exhibits antibacterial properties and biocompatibility in human body, and can enhance mechanical properties of magnesium alloys. Influence of Ag addition (0, 0.2, 0.4 and 0.8 wt%) on microstructure and corrosion behavior of Mg–Nd–Zn–Zr alloys was investigated in this study. Chemical composition, phase, microstructure and corrosion behavior of the alloys were studied. The microstructure was refined with increasing Ag addition, and the volume of the second phase increased. Ag was found in the second phase. Both the mass loss and hydrogen evolution test results showed that the alloy with 0.2 wt% Ag addition exhibited corrosion resistance that approximatied that of the alloy without Ag addition in simulated body fluid, while the corrosion resistance declines apparently with increasing Ag addition.