Mechanical and degradation properties of zinc adopted magnesium alloys for biomedical application

The demand for short-term degradable implant in bone fixation applications is growing steadily due to the aging population worldwide. Degradable implants have the advantage that the second surgery for implant removal is not required. Magnesium is one of the best candidates because it is biodegradable, physiologically compatible and even stimulates bone reconstruction. However, the high degradation rate of pure magnesium in human body fluids may prevent its wider application. In this study, Zinc (Zn) was added in magnesium (Mg) to improve its properties. The effects of five different weight percentage of Zinc (2%, 4%, 6%, 8%, 10%) were investigated. The microstructure and mechanical properties evolution of the alloys were characterized and evaluated using optical microscopy, Scanning Electron Microscope (SEM), tensile test and Vickers hardness test, while degradation behavior was examined using electrochemical corrosion test. The binary Mg-Zn cast alloy with 6 wt. % zinc content (labeled as Mg-6Zn) shows optimum mechanical strength with slowest degradation rate.