Hyper-Range Amorphization Unlocks Superior Damage Tolerance in Alloys

Area of Science:

• Materials Science
• Mechanical Engineering
• Alloy Design

Background:

• Shear bands are primary failure mechanisms in alloys, limiting damage tolerance.
• Short-range amorphization can mitigate shear effects but is typically nanoscale.

Purpose of the Study:

• To extend amorphization to the micrometer scale in multi-principal element alloys.
• To develop a strain engineering-based mechanism for enhanced material properties.

Main Methods:

• Continuous compression strain-training of alloy micropillars from low to high strain rates.
• Generation of a dislocation gradient to drive topological disorder network formation.
• Characterization of hyper-range amorphization extending over one-third of the micropillar height.

Main Results:

• Achieved micrometer-scale amorphization, termed hyper-range amorphization.
• Amorphous bands exhibited dynamic atomic disorder and lattice recovery, dissipating shear stress.
• The alloy reached ceramic-level compressive strength (~6.5 GPa) with ~59.1% plasticity.

Conclusions:

• Strain engineering enables micrometer-scale amorphization, a viable pathway for alloy enhancement.
• This method fundamentally replaces shear-dominated failure mechanisms.
• Enhanced structural stability and energy dissipation capacity were achieved.