Composite Coatings for Magnesium-Based Implants with Enhanced Corrosion Resistance

Bone fractures are increasingly common nowadays, with innovative surgical solutions emerging, such as the utilization of biodegradable metallic implants instead of permanent fixation implants. Failure to remove the currently in-use permanent implants may lead to problems such as infection, bone resorption, or stress concentration on the fixation locations. Magnesium and its alloys exhibit a biodegradable nature in aqueous environments, rendering them appealing for diverse biomedical applications where permanent existence in the body is not advisable. In addition, magnesium alloys offer superior biocompatibility and mechanical properties, which resemble those of natural bones compared to other biodegradable metals. The main challenge facing the utilization of magnesium for bone fracture repair appears in maintaining its mechanical integrity due to its rapid corrosion rate and, hence, the release of corrosion byproducts in the physiological environment. In this study, we have formulated a Micro-Arc-Oxidation coating and conducted a comprehensive assessment of its corrosion rate using electrochemical tests, pH measurements, and weight loss calculations against uncoated magnesium samples. The results showed how the Micro-Arc-Oxidation coating would result in decreasing the corrosion rates of magnesium in an aqueous environment, making it a suitable alternative for biomedical implants.