Stress relaxation in high-entropy Pd20Pt20Cu20Ni20P20 metallic glass: Experiments, modeling and theory

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

“…With increasing temperature, a large increase of the normalized loss modulus is observed, which corresponds first to the slow 𝛽𝛽 relaxation and, eventually, the primary 𝛼𝛼 relaxation. Unlike the La-based MGs, that show an evident slow 𝛽𝛽 relaxation peak [19,27], and the Zr-and Pt-based MGs, that show only an excess wing [27], the Pd20Pt20Cu20Ni20P20 HE-MG exhibit a broad shoulder corresponding to slow 𝛽𝛽 relaxation as shown in Fig. 1 (b).…”

“…The thermal properties of the Pd20Pt20Cu20Ni20P20 HE-MG were determined by differential scanning calorimetry (DSC, Netzsch 202) in a nitrogen atmosphere with a heating rate of 10 K/min. The glass transition temperature 𝑇𝑇 𝑔𝑔 = 572 K and the onset crystallization temperature 𝑇𝑇 𝑥𝑥 = 632 K were determined [27]. The large supercooled liquid region (SLR) ∆𝑇𝑇 = 𝑇𝑇 𝑥𝑥 − 𝑇𝑇 𝑔𝑔 = 60 K indicates an excellent glass forming ability.…”

“…Recent investigations showed that the slow 𝛽𝛽 relaxation closely relates to the plastic deformation and the nature of the glass transition of MGs [42]. Besides, Pd20Pt20Cu20Ni20P20 HE-MG exhibits a ultrahigh activation energy of slow 𝛽𝛽 relaxation, suggesting that HE-MGs may possess a higher energy barrier for the dynamic 𝛽𝛽 relaxation [27]. can be captured without any extensive strain hardening.…”

“…HEAs exhibit superior properties, i.e. high configurational entropy, large lattice distortion, sluggish diffusion and cocktail effect [25][26][27]. Inheriting some distinct properties of both MGs and HEAs, high-entropy metallic glasses (HE-MGs) exhibit superior properties (e.g.…”

Identifying stress-induced heterogeneity in Cu20Zr20Ni20Ti20Pd20 high-entropy metallic glass from machine learning atomic dynamics

“…A series of research on creep reported that HEMGs have a smaller serration during plastic flow [21] , a smaller apparent activation volume [19,22,23] , and a slower annihilation of free volume [22] , than conventional MGs. Such a mechanical behavior of HEMGs is interpreted by a more homogeneous atomic arrangement [24,25] with less loose packing "defects" [24] , from the structural perspective, and it is also caused by the sluggish atomic diffusion [20,26] and the inactive response of atomic motion to stress [19,26] , in the view of dynamics. However, the evidence and understanding of heterogeneity at the atomic level are rare, which attracts our interest in unfolding the atomic mechanism of stress-induced heterogeneity in HEMGs.…”