Mechanical property and structural changes by thermal cycling in phase-separated metallic glasses. (10th July 2021) - Tang, Y.
Graphical abstract: Highlights: Effects of thermal cycling on the spatial heterogeneity of MGs have been investigated. Ti41 Zr25 Be28 Fe6, Zr42 Y14 Co22 Al22 and Zr56 Co14 Cu14 Al16 MGs show different the structure-property relationships under the same cryo-thermal cycling treatment. The intrinsic correlation between the spatial heterogeneity and thermal cycling is proposed. Abstract: Nondestructive cryogenically thermal cycling has been a simple but effective treatment to enhance mechanical properties of glassy materials. However, how the structural heterogeneities on nanometer scales are affected by thermal cycling is still an issue. Here, we report the response of spatial heterogeneities in three selected Ti41 Zr25 Be28 Fe6, Zr56 Co14 Cu14 Al16 and Zr42 Y14 Co22 Al22 (at.%) metallic glasses (MGs) with different compositions to the thermal cycling, which show significantly different structure and properties after the same treatments and could be ascribed to the joint contribution of relaxation and rejuvenation induced by thermal cycling. The rejuvenation is initially prevailed in a Zr-Y-containing MG, whereas the relaxation is dominant in a Cu-Co-containing MG, both eventually entering into a dynamic equilibrium state. By employing nanometer-scale structural models, the intrinsic correlation between the spatial heterogeneity and thermal cycling is proposed. The discovery could provide the fundamental understanding of the role of spatial heterogeneity in influencing the macroscopic properties of MGs via thermal cycling and help design high-performance glassy materials by tailoring their atomic structures with suitable thermal treatments.