Origin of the time-dependent corrosion behavior of biodegradable Mg-Si-Zn alloys in simulated body fluid

Author(s)

de Gouveia, Guilherme Lisboa ; Spinelli, Jose Eduardo ; Koga, Guilherme Yuuki

• Document type: Journal article
• Source: Corrosion Science; v. 237, p. 17-pg., 2024-08-07.

Abstract

The corrosion behavior of Mg-0.6%Si-2%Zn alloys in simulated body fluid was studied to understand the time- dependent processes and interfacial phenomena. The alloy's microstructure includes Mg-rich dendrites within eutectic microconstituent. Electrochemical responses showed minimal dependence on dendritic-spacing. Initial immersion (12.2-hour) formed a protective layer, indicated by potential elevation, polarization resistance escalation, and changes in Nyquist and Bode plots. However, between 12.2- and 168.4-hour, the protective layer integrity decreased, with observable corrosion. The corrosion mechanism involved protective layer formation followed by cracking induced by Pilling-Bedworth ratio and high H2 2 evolution kinetics. This time-dependent corrosion resistance resembles both corrosion-resistant and corrosion-sensitive Mg alloys, showcasing challenges in accurate assessment. (AU)

• FAPESP's process: 19/01432-8 - Microstructure development, corrosion and mechanical resistances of Mg-Si and Mg-Si-(x) alloys for biomedical application
• Grantee: Guilherme Lisboa de Gouveia
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 23/06107-3 - Study of the growth of AlFe primary phases in Al alloys and of intermetallic layers in Sn-Bi-X/copper joints
• Grantee: José Eduardo Spinelli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 22/01895-0 - Evaluation of the microstructural evolution of biomedical absorbable Mg alloys during corrosion process through non-destructive 3D analysis using the Absorption Contrast X-ray Tomography (ACT) technique
• Grantee: Guilherme Lisboa de Gouveia
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate