Regular Article

Effect of the physical aging on the secondary β relaxation process in a La-based metallic glass

¹ School of Mechanics and Civil & Architecture, Northwestern Polytechnical University, Xi’an 710072, P.R. China
² Queen Mary University of London Engineering School, Northwestern Polytechnical University, Xi'an 710072, P.R. China

^* e-mail: guojian.lyu@nwpu.edu.cn; qjczy@nwpu.edu.cn

Received: 5 February 2023
Received in final form: 20 March 2023
Accepted: 6 April 2023
Published online: 8 May 2023

Abstract

Dynamic mechanical relaxation processes, i.e., main (α) relaxation and secondary (β) relaxation, are important issues to understand mechanical deformation, atomic diffusion as well as glass transition phenomenon of metallic glasses. In current work, La₆₈Ni₁₅Al₁₅Cu₂ metallic glass was selected as a protocol glass system. Mechanical relaxation processes were probed by dynamic mechanical analysis. The effects of annealing at different temperatures were analyzed by Kohlrausch–Williams–Watts (KWW)-type equation. The Kohlrausch exponent β_KWW reflects the deviation from a single Debye relaxation, indicating the fact that dynamics in metallic glass are actually heterogeneous originating from the structural heterogeneity. The effects of thermal treatments were also discussed, which provides a potential solution to tune the relaxation behaviors in metallic glasses.