Local intragranular misorientation accelerates corrosion in biodegradable Mg.

Area of Science:

• Biomaterials Science
• Materials Science
• Corrosion Engineering

Background:

• Magnesium (Mg)-based implants are crucial in biomedical applications due to their biodegradability.
• Understanding factors influencing Mg degradation is key for effective clinical use.
• Local misorientations within grains are a critical microstructural feature affecting Mg properties.

Purpose of the Study:

• To investigate the impact of local misorientations on the corrosion behavior of high-purity magnesium (HPM).
• To correlate microstructural features with corrosion resistance in HPM for biomedical applications.
• To explore methods for controlling Mg degradation through microstructure design.

Main Methods:

• Microstructure characterization using techniques to identify local misorientations.
• Corrosion measurements to assess the degradation rate and behavior of HPM.
• Deformation (hot rolling, compression) and annealing treatments to control microstructure.

Main Results:

• Local misorientations introduced by deformation promote corrosion around grain boundaries (GB).
• This grain boundary corrosion significantly reduces the overall corrosion resistance of HPM.
• Annealing effectively eliminates local misorientations, thereby preventing GB corrosion.

Conclusions:

• Local misorientation is a critical factor governing the corrosion resistance of HPM.
• Controlling local misorientations through annealing can enhance the corrosion resistance of Mg implants.
• Microstructure design, specifically managing grain orientation, offers a pathway to tailor Mg degradation for biomedical applications.