A generalized solid strengthening rule for biocompatible Zn-based alloys, a comparison with Mg-based alloys

Area of Science:

• Materials Science
• Computational Materials Science
• Alloy Design

Background:

• Solid solution strengthening is crucial for high-performance biocompatible magnesium (Mg)-based alloys.
• Its application to zinc (Zn)-based alloys remains limited and poorly understood.
• Understanding solute interactions is key to developing advanced Zn alloys.

Purpose of the Study:

• To systematically investigate solute strengthening mechanisms in Zn-based alloys.
• To compare solute strengthening in Zn-based alloys with that in Mg-based alloys.
• To establish predictive guidelines for designing novel Zn-based alloys.

Main Methods:

• Utilized an ab initio informed Peierls-Nabarro model.
• Employed Leyson et al.'s strengthening model for solute analysis.
• Compared solute strengthening parameters (volume misfit ε_b and chemical misfit ε_SFE) between Zn and Mg alloys.

Main Results:

• Identified an inverse relationship between volume misfit (ε_b) and chemical misfit (ε_SFE) in both alloy types.
• Observed distinct solute behavior in Zn-based alloys: typically positive ε_b and negative ε_SFE, unlike Mg-based alloys.
• Developed a generalized scaling diagram using ε_b and ε_SFE for rapid assessment of solute strengthening.

Conclusions:

• Alkaline-earth and rare earth elements show promise as superior strengtheners for Zn-based alloys.
• The developed scaling diagram provides a predictive tool for designing biocompatible Zn alloys.
• This work offers a generalizable rule for enhancing solid solution strengthening in metallic materials.