Rejuvenation by enthalpy relaxation in metallic glasses
نویسندگان
چکیده
Structural relaxation can be induced by annealing and usually leads to embrittlement in metallic glasses (MGs). Here, we show that a relaxed MG obtained an as-cast at temperature (annealing temperature, Ta) below its fictive suitably rejuvenated thermal treatment of the higher than Ta. The effect is driven enthalpy relaxation, endothermic reaction upon heating MG. This rejuvenation lifts energy state towards Importantly, found plasticity fracture toughness optimally samples exceed those sample, reversing relaxation-induced sample. An analysis structural changes shows packing density, rather ordering atomic structure, responsible for effects rejuvenation. observed may originate from recovery loosely packed regions structure were densified during annealing. Our findings are significant tailoring mechanical properties MGs.
منابع مشابه
Thermal rejuvenation in metallic glasses
Structural rejuvenation in metallic glasses by a thermal process (i.e. through recovery annealing) was investigated experimentally and theoretically for various alloy compositions. An increase in the potential energy, a decrease in the density, and a change in the local structure as well as mechanical softening were observed after thermal rejuvenation. Two parameters, one related to the anneali...
متن کاملRelaxation of bulk metallic glasses studied by mechanical spectroscopy.
The relaxational dynamics in metallic glasses (MGs) is investigated by using mechanical spectroscopy. The spectra show that in MGs there are two relaxations: (i) the α relaxation, linked to the glass transition, as observed in other classes of amorphous materials; and (ii) the β relaxation, well observed below the glass transition, with an intensity strongly dependent on the MG composition, the...
متن کاملStructural relaxation kinetics defines embrittlement in metallic glasses
Article history: Received 5 December 2017 Received in revised form 22 January 2018 Accepted 23 January 2018 Available online xxxx Structural relaxation during isothermal annealing, quantified by enthalpy recovery of Zr44Ti11Cu10Ni10Be25 towards its metastable equilibrium and correlation to embrittlement, quantified through fracture toughness, KQ, is studied. Enthalpy relaxation over time obeys ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Acta Materialia
سال: 2022
ISSN: ['1873-2453', '1359-6454']
DOI: https://doi.org/10.1016/j.actamat.2022.118376