摘要
High-temperature deformation has been demonstrated as an effective measure to rejuvenate and optimize the mechanical properties of metallic glasses(MGs).Clarifying the competition between aging and rejuvenation during high-temperature deformation is helpful in rejuvenating MGs accurately.Signatures of aging and rejuvenation in a La_(30)Ce_(30)Ni_(10)Al_(20)Co_(10)MG were investigated via high-temperature deformation and mechanical relaxation.The coupling of thermal history,aging,and mechanical disordering determines the transient deformation and the structural state of MGs.The stress overshoot and anelastic deformation induce structural rejuvenation,increasing the concentration of defects and erasing thermal history.Therefore,the eventually steady-state condition is dependent on ambient temperature and strain rate instead of the initial structure.Furthermore,the one-to-one relationship between defect concentration and strain rate clarifies the structural nature of rejuvenation in amorphous materials.Such a relationship also contributes toward a comprehensive understanding of the structural rejuvenation behavior in amorphous materials.
基金
supported by the National Natural Science Foundation of China(NSFC)(Grant No.51971178),financially supported by NSFC(Grant No.12072344)
the Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province(Grant No.2021JC-12)
the Natural Science Foundation of Chongqing(Grant No.cstc2020jcyj-jq X0001)
sponsored by the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(Grant No.CX2021015).
the Youth Innovation Promotion Association of the Chinese Academy of Sciences
financial support from the Research Grant Council(RGC)
the Hong Kong government through the General Research Fund(GRF)(Grant Nos.City U11200719,and City U11213118)。
