Large tensile plasticity induced by pronounced β-relaxation in Fe-based metallic glass via cryogenic thermal cycling

The effects of cryogenic thermal cycling (CTC) treatment on tensile plasticity and structure change of [(Fe0.5Co0.5)(0.75)B0.2Si0.05](96)Nb-4 metallic glass (MG) ribbons were systematically investigated. Pronounced beta-relaxation peaks locating at 643 and 693 K were observed after CTC treatment with diverse thermal temperatures. Specifically, the CTC treated samples exhibiting most remarkable beta-relaxation showed tensile plastic strain of 5.2% at 643 K and 4% at 693 K, while the as-quenched sample only showed tensile plastic strain of 3% at 643 K and 2.1% at 693 K. The pronounced beta-relaxation and enhanced tensile plasticity are considered to be originated from the increased structural heterogeneity. The separate beta-relaxation peaks result from the different sizes/types of shear transformation zones induced by oscillatory (rejuvenation-relaxation) behavior during thermal cycling. Our results indicate that the CTC treatment has a significant impact on the energy states and structural heterogeneity, which makes it a powerful means to modify the mechanical properties of MGs. (C) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The effects of cryogenic thermal cycling treatment on the tensile plasticity and structure change of metallic glass ribbons were systematically investigated. The study found that the treated samples showed pronounced beta-relaxation peaks and enhanced tensile plasticity. This suggests that cryogenic thermal cycling treatment has a significant impact on the energy states and structural heterogeneity of metallic glasses.