Avalanches in Cu-Zr-Al metallic glasses.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Mechanical Engineering

Background:

• Metallic glasses possess unique mechanical properties.
• Stress drops in metallic glasses are analogous to avalanches.
• Understanding these avalanches is key to predicting material behavior.

Purpose of the Study:

• Investigate stress drop avalanches in Cu-Zr-Al metallic glasses.
• Analyze the impact of element concentration and cooling rate on mechanical properties.
• Characterize the gap distribution and avalanching behavior across different strain levels.

Main Methods:

• Athermal quasistatic shear simulations.
• Systematic variation of element concentrations in Cu-Zr-Al.
• Modification of cooling rates for pure Cu-Zr (50/50).

Main Results:

• Mechanical properties align with experimental findings.
• Systems exhibit a gap distribution with a small positive exponent at small strains.
• Critical avalanching behavior emerges near the yield point.
• Post-yield stress drops demonstrate universality.
• The gap distribution becomes flat after yielding.

Conclusions:

• The study elucidates the nature of stress-drop avalanches in metallic glasses.
• Results highlight universal characteristics of mechanical behavior in these materials.
• Findings contribute to a deeper understanding of plasticity and failure mechanisms in metallic glasses.