Psychology

Metallurgy

Materials science

Alloy

Zirconium

Social psychology

Fluorescence

Composite material

Plasticity

Physics

Amorphous metal

Hydrostatic pressure

Melting point

Rejuvenation

Optics

Relaxation (psychology)

Gerontology

Quenching (fluorescence)

Glass transition

Enthalpy

Polymer

Medicine

Thermodynamics

Nature Communications

Rejuvenation of metallic glasses, bringing them to higher-energy states, is of interest in improving their plasticity. The mechanisms of rejuvenation are poorly understood, and its limits remain unexplored. We use constrained loading in compression to impose substantial plastic flow on a zirconium-based bulk metallic glass. The maximum measured effects are that the hardness of the glass decreases by 36%, and its excess enthalpy (above the relaxed state) increases to 41% of the enthalpy of melting. Comparably high degrees of rejuvenation have been reported only on microscopic scales at the centre of shear bands confined to low volume fractions. This extreme rejuvenation of a bulk glass gives a state equivalent to that obtainable by quenching the liquid at ~1010 K s-1, many orders of magnitude faster than is possible for bulk specimens. The contrast with earlier results showing relaxation in similar tests under tension emphasizes the importance of hydrostatic stress.

Extreme rejuvenation and softening in a bulk metallic glass