Effects of chromium ion implantation voltage on the corrosion resistance and cytocompatibility of dual chromium and oxygen plasma-ion-implanted biodegradable magnesium

Magnesium is modified by chromium ion implantation at different voltages followed by oxygen ion implantation to improve the corrosion resistance and cytocompatibility. All the implanted samples exhibit improved corrosion resistance and the ones implanted at a lower voltage yield better results. The chromium-rich layer with chromium in the metallic state beneath the protective oxide film may undermine the electrochemical stability by inducing galvanic effects which lead to poorer corrosion resistance. Although dual Cr–O plasma immersion ion implantation promotes osteoblast adhesion and proliferation on the magnesium samples and produces a more favorable environment for osteoblast growth, optimal results require careful selection of the ion implantation voltage.