Substantially enhanced homogeneous plastic flow in hierarchically nanodomained amorphous alloys

Area of Science:

• Materials Science
• Metallurgy
• Amorphous Alloys

Background:

• Metallic glasses often suffer from mechanical instability due to shear bands.
• Previous approaches focused on topological structures to mitigate this issue.

Purpose of the Study:

• To develop a compositional design strategy for nanoscale chemical heterogeneity in metallic glasses.
• To enhance homogeneous plastic flow and mechanical properties under both compression and tension.

Main Methods:

• Fabrication of a Ti-Zr-Nb-Si-XX/Mg-Zn-Ca-YY hierarchically nanodomained amorphous alloy.
• Characterization of mechanical properties under compression and tension.
• Analysis of dynamic atomic intermixing at nanodomains during plastic flow.

Main Results:

• The alloy exhibited ~2% elastic strain and ~40% homogeneous plastic flow with strain hardening in compression.
• Performance surpassed that of mono- and hetero-structured metallic glasses.
• Observed dynamic atomic intermixing between nanodomains, preventing interface failure.

Conclusions:

• Nanoscale chemical heterogeneity is an effective strategy to enhance plastic flow in metallic glasses.
• Dynamic atomic intermixing contributes to improved mechanical stability and ductility.
• This approach offers a pathway for developing amorphous materials with ultrahigh strength and large plasticity.