Comparison of structural heterogeneity in Zr- and Pd-based metallic glasses

• Published in: European physical journal. Applied physics Vol. 98; p. 18
• Main Authors: Wang, Hao, Zhu, Sheng-Li, Cui, Zhen-duo
• Format: Journal Article
• Language: English
• Published: 2023
• ISSN: 1286-0042; 1286-0050
• DOI: 10.1051/epjap/2023230026

Metallic glasses (MGs) are known to exhibit a nanoscale heterogeneous structure that consists of a weakly bonded region (WBR) and a strongly bonded region (SBR), but its characterization is not yet fully understood. This study investigates the structural heterogeneity of Zr- and Pd-based MGs using a dynamic viscoelastic model. Volume fraction ( V ) and elastic modulus ( E c ) are independently derived from the model to characterize each region. In addition, the structural heterogeneity is evaluated using χ  =  VE c,WBR / VE c,total . As a result, the strong Zr-based MG is estimated to own approximately 28% of V WBR , approximately 87% of E c,WBR / E c,SBR , and χ ∼ 0.241. On the other hand, the fragile Pd-based MG is estimated to own approximately 26% of V WBR , approximately 70% of E c,WBR / E c,SBR , and χ ∼ 0.208. Furthermore, a comparison of χ , fragility, and Poisson's ratio shows that as χ increases, fragility decreases and Poisson's ratio increases. Notably, the diversification of constituent elements is inversely related to χ , fragility, and Poisson's ratio in the Zr- and Pd-based MGs. Thus, the existing understanding of the structural heterogeneity inherent in MGs is updated using the constructed dynamic viscoelastic model in this study.