Comparison of the short and long-term degradation behaviors of as-cast pure Mg, AZ91 and WE43 alloys

Ocal E. B., Esen Z., Aydinol K., Dericioğlu A. F.

MATERIALS CHEMISTRY AND PHYSICS, vol.241, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 241
  • Publication Date: 2020
  • Doi Number: 10.1016/j.matchemphys.2019.122350
  • Journal Name: MATERIALS CHEMISTRY AND PHYSICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: Magnesium alloys, Corrosion, Biodegradation, Microgalvanic corrosion, In-vitro, ELECTROCHEMICAL CORROSION BEHAVIOR, BIODEGRADABLE MAGNESIUM ALLOYS, BODY-FLUID SOLUTION, BONE REPAIR, MICROSTRUCTURE, MECHANISMS, ZN, MORPHOLOGY, PART
  • Middle East Technical University Affiliated: Yes

Abstract

The corrosion behaviors of pure magnesium, AZ91, and WE43 alloys have been evaluated by weight loss, hydrogen evolution rate, pH change measurements and potentiodynamic polarization as well as electrochemical impedance spectroscopy (EIS) methods. Main corrosion product formed on the surface of Mg/Mg-alloys after immersion of 24 h was Mg(OH)(2) on the other hand, at the end of the 20 days additional CaCO3 which was found to display a critical role in degradation characteristics of the samples, was found. Examination in the cross section of the polished surfaces revealed that protective layers became thicker and corrosion rate of the samples decreased possibly due to increased protective abilities of the surfaces. Intermetallics in AZ91 and WE43 alloys acted as cathodic centers and induced micro galvanic corrosion. Undermining of intermetallics in WE43 alloy intensified the corrosion rate. AZ91 alloy exhibited the lowest corrosion rate among the samples when tested in simulated body fluid (SBF).