BPCPPDYSOE21 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 21: Glasses and Glass Transition 2 (joint session DY/CPP)

CPP 21.4: Vortrag

Mittwoch, 24. März 2021, 12:00–12:20, DYc

Decelerated aging in metallic glasses by low temperature thermal cycling — •Fathollah Varnik — ICAMS, Ruhr-University Bochum, Germany

It has been recently proposed that deep temperature cycling of metallic glasses may lead to a rejuvenation and improve their ductility. Here, we investigate this issue via extensive molecular dynamics simulations of a generic model glass former. We disentangle the effects of aging from those of thermal treatment and show that aging is slowed down but not stopped -- neither reversed -- during thermal cycling. These observations are corroborated further by a survey of energy distribution, which continues narrowing, albeit with a smaller rate. Our results are in qualitative agreement with recent differential scanning calorimetry measurements on different bulk metallic glasses, which show no measurable rejuvenation upon deeply cooled (cryogenic) thermal cycling. This applies both to as-quenched and well-annealed samples.