Rejuvenation by enthalpy relaxation in metallic glasses

The authors have requested that this preprint be withdrawn due to author disagreement.

Rejuvenation by enthalpy relaxation in metallic glasses

Usually structural relaxation would lead to embrittlement in metallic glasses (MGs). Here, we show that rejuvenation of relaxed MGs is achieved simply by a thermal exposure at a temperature higher than the annealing temperature (but below glass transition temperature). The effect is driven by enthalpy relaxation (an endothermic reaction upon heating relaxed MGs). This rejuvenation lifts the energy state of the relaxed glass towards that of the as-cast glass. Importantly, we demonstrate that the plasticity and fracture toughness of the rejuvenated samples exceed those of the as-cast state. An analysis of the structural changes shows that the rearrangement of cluster connectivity at the medium-range length scale is responsible for the rejuvenation. Our finding is significant for the tailoring of the mechanical properties of metallic glasses.