New Zn3Mg-xY Alloys: Characteristics, Microstructural Evolution and Corrosion Behavior

Area of Science:

• Biomaterials Science
• Materials Science
• Corrosion Engineering

Background:

• Biodegradable metallic implants are gaining traction, with zinc-based alloys emerging as a promising alternative to magnesium and iron-based materials.
• Magnesium (Mg) is known to enhance the mechanical properties of zinc (Zn) alloys.
• Investigating the influence of a third element, yttrium (Y), is crucial for further optimizing Zn alloy performance.

Purpose of the Study:

• To analyze the effect of yttrium (Y) addition on the mechanical properties and corrosion resistance of ternary zinc-magnesium-yttrium (ZnMgY) biodegradable alloys.
• To compare the performance of ZnMgY alloys with pure zinc and binary ZnMg alloys.
• To understand the role of newly formed Y-containing phases in alloy behavior.

Main Methods:

• Ternary ZnMgY alloys were fabricated using induction melting under an argon atmosphere.
• Materials characterization involved scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and microhardness testing.
• Corrosion behavior was assessed through linear and cyclic potentiometry and immersion tests in Dulbecco solution.

Main Results:

• Addition of Y to ZnMg alloys significantly increased microhardness and indentation Young's Modulus.
• The formation of YZn12 intermetallic phases was observed, which possess a more noble electrochemical potential than pure zinc.
• All tested alloys exhibited generalized corrosion in Dulbecco solution, with evidence of aggressive galvanic corrosion linked to the new Y phases.

Conclusions:

• Yttrium addition is effective in improving the mechanical properties of ZnMg biodegradable alloys.
• The presence of YZn12 phases influences the corrosion mechanism, potentially leading to galvanic effects.
• ZnMgY alloys show potential for biomedical applications, but their corrosion behavior requires careful consideration.