title: A mechanistic in vitro study of the microgalvanic degradation of secondary phase particles in magnesium alloys.
abstract: The aim of this work was to understand the effect of microgalvanic degradation on secondary phase particles in magnesium alloys under in vitro condition. Pure magnesium and Mg17 Al12 (β-phase) were galvanically coupled in simulated body fluid and the degradation behavior was studied using electrochemical impedance spectroscopy. The galvanic coupling produced a phosphate/carbonate layer on the β-phase, which initially increased the degradation resistance. However, the deposited phosphate/carbonate layer rapidly degraded once the galvanic coupling was removed, and β-phase exhibited similar degradation resistance to that of pure magnesium. A phenomenological model has been presented, demonstrating the galvanic coupling effect.
authors.affiliation: Biomaterials and Engineering Materials (BEM) Laboratory, School of Engineering and Physical Sciences, James Cook University, Townsville, Queensland, 4811, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Walter
authors.forename: M Bobby
authors.initials: MB
authors.lastname: Kannan
mesh_terms: D000497:Alloys / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D001826:Body Fluids; D002254:Carbonates / Q000737:chemistry; D003343:Corrosion; D058266:Dielectric Spectroscopy; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D002254:Carbonates; D010710:Phosphates; D008274:Magnesium
keywords: biodegradation; galvanic effect; in vitro test; magnesium