J. Mater. Sci. Technol. ›› 2022, Vol. 107: 82-91.DOI: 10.1016/j.jmst.2021.07.052

• Research Article • Previous Articles     Next Articles

Analysis of the anelastic deformation of high-entropy Pd20Pt20Cu20Ni20P20 metallic glass under stress relaxation and recovery

Y.J. Duana,b, L.T. Zhanga, T. Wadac, H. Katoc, E. Pined b, D. Crespob, J.M. Pelletierd, J.C. Qiaoa,*()   

  1. aSchool of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi’an 710072, China
    bDepartment of Physics, Institute of Energy Technologies, Universitat Politècnica de Catalunya, Barcelona 08019, Spain
    cInstitute for Materials Research, Tohoku University, Sendai 980-8577, Japan
    dUniversitéde Lyon, MATEIS, UMR CNRS5510, Bat. B. Pascal, INSA-Lyon, F-69621 Villeurbanne Cedex, France
  • Received:2021-05-25 Revised:2021-05-25 Accepted:2021-05-25 Published:2022-04-30 Online:2022-04-28
  • Contact: J.C. Qiao
  • About author:*E-mail address: qjczy@nwpu.edu.cn(J.C. Qiao).

Abstract:

The anelastic deformation behavior of Pd20Pt20Cu20Ni20P20 high-entropy metallic glass was probed by monitoring the stress relaxation and recovery processes. The stress relaxation under consecutive strain steps can be described by the Kohlrausch-Williams-Watts (KWW) function. In addition, considering a hierarchy of relaxation processes related to the structural heterogeneity, a constitutive model is proposed in order to describe the whole process of stress relaxation and determine the contribution of different time scales. Moreover, a crossover from stochastic activation to percolation of flow defects with the ultimate strain can be observed during stress relaxation process. The anelastic recovery process after a strain step is studied as a function of the initial strain level and characterized by means of a direct spectrum analysis. The peaks in the recovery time-spectra revealed the evolution of flow defects in Pd20Pt20Cu20Ni20P20 high-entropy metallic glass. The understanding of the atomic free-volume zones effect and the anelastic deformation provides important insight into how atomic structural features affect the deformation behavior of high-entropy metallic glasses, and may provide a new avenue into the improvement of their mechanical properties.

Key words: High-entropy metallic glass, Stress relaxation, Anelastic deformation, Flow defects, Free-volume zones