Improved corrosion resistance on biodegradable magnesium by zinc and aluminum ion implantation

Magnesium and its alloys have promising applications as biodegradable materials, and plasma ion implantation can enhance the corrosion resistance by modifying the surface composition. In this study, suitable amounts of zinc and aluminum are plasma-implanted into pure magnesium. The surface composition, phases, and chemical states are determined, and electrochemical tests and electrochemical impedance spectroscopy (EIS) are conducted to investigate the surface corrosion behavior and elucidate the mechanism. The corrosion resistance enhancement after ion implantation is believed to stem from the more compact oxide film composed of magnesium oxide and aluminum oxide as well as the appearance of the β-Mg17Al12 phase.

► Zn and Al ions were implanted into Mg to simulate AZ alloys. ► Initial corrosion resistance of the implanted sample was much larger than Mg, AZ31 and AZ91. ► Ions implantation produces compact oxide film and β-Mg17Al12 phases on the surface.