Electrochemical corrosion behavior of AZ91D magnesium alloy-graphene nanoplatelets composites in simulated body fluids

Abstract

Magnesium-based materials have received extensive attention as biomedical implant materials due to their good mechanical properties and ability to degrade naturally in vivo. However, the limitation of magnesium-based materials in medical applications is that the corrosion rate is too rapid to maintain the mechanical integrity of implants during bone healing. The electrochemical corrosion behavior of AZ91D magnesium alloy-graphene nanoplatelets (AZ91D-GNPs) composites in simulated body fluid (SBF) solution was investigated. The corrosion behavior was characterized by microscopic observation, dynamic potential polarization and Nyquist diagram. The influence of different GNPs content and different heat treatment on the corrosion behavior of AZ91D magnesium alloy was determined. The results show that the corrosion resistance of AZ91D-GNPs composites is the highest when the content of GNPs is 0.6 wt%, and the corrosion rate is 2.7549 mm/a. In addition, after solution treatment, the corrosion rate is 0.5179 mm/a, which is reduced by 81%. Solution treatment can effectively improve the corrosion resistance of AZ91D-GNPs composites.