Structural rejuvenation in a bulk metallic glass induced by severe plastic deformation

Mechanical Properties of Metallic Glasses

“…However, they can be restored by annealing above T g . Also during heavy mechanical deformation parts of the sample in or near the shear bands become liquid, so T eff is raised back above T g , and the sample becomes "rejuvenated" [62]. On the other hand, other properties, such as magnetic transition temperature [63] and internal friction [64], can be reversibly changed even when annealing is performed below T g .…”

Long range stress fields and cavitation along a shear band in a metallic glass: The local origin of fracture

“…The dynamics of shear banding, as well as the localization to the nm-scale make it extremely challenging to probe the structural state of the planar defect, and one has to rely on molecular dynamics simulations to obtain relevant structural insights on different shear-banding stages [8,9] that ultimately lead to failure. Therefore post mortem structural probing with either X-rays [10], neutrons [11], positrons [12], electrons [13], or nanomechanical methods [14,15] have been employed. All of these methods give in summary a similar main insight, which is that the deformed MG structure has widened and softened.…”

Pronounced Structural Rejuvenation in Zr₅₀Cu₄₀Al₁₀ Metallic Glass Strained by Torsional Straining at Elevated Temperature

“…It is known that the mechanical deformation converts the mechanical energy into thermal energy, such as inside of shear bands. 9,15,16) The atomic displacement out of the atomic cage due to deformation increases the randomness of the structure and results in the rejuvenation. For the HPT at elevated temperature, apparently torsional straining is able to translate to the internal energy easily by extensive atomic movement and result in an increase in the rejuvenated volume.…”

“…8) Pair distribution function (PDF) analysis on the HPT deformed sample signifies that torsional straining removes the atomic distribution away from the PDF peaks and redistributed it between the PDF peaks, which can be interpreted by the increase in free and anti-free volume. 9) This change is opposite to the tendency expected for relaxation or crystallization and is thus referred to as structural rejuvenation. Both introduction of free and antifree volume and modification of chemical short-range ordering atomic arrangement are referred as rejuvenated structure.…”