Structural heterogeneity in levitated glassy alloys with different undercoolings

The structural evolution in the undercooled liquid plays an essential role in comprehending the crystal-lization mechanism, which is of benefit to understand the glass-forming ability (GFA), the thermal stability, and the development of glassy alloy (GA) with excellent properties. In this work, Zr61Ti2Cu25Al12 GAs with different undercooled states were obtained by means of electromagnetic levitation. The Zr61Ti2Cu25Al12 GA can achieve an undercooling degree of 226 K, which is larger than previously reported GAs. Calorimetric analysis indicates a more relaxed state occurs in the GA cooled from the larger undercooling. Hardness tests show that deep undercooling can lead to a significant increase in hardness compared to a low undercooling level. It might be attributed to a liquid-liquid transition, bringing out an obvious change in the atomic volume of the glassy phase. In addition, a pronounced ordered structure apparently exists when the system reaches the larger undercooling degree. Our findings provide a new perspective for the study of the un-dercooled liquid, and the solidification kinetics of GAs.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

In this study, Zr61Ti2Cu25Al12 glassy alloys (GAs) with different undercooled states were obtained, and it was found that deep undercooling can significantly increase the hardness and there may be an apparent ordered structure at larger undercooling degrees. These findings provide a new perspective for the study of the solidification kinetics of GAs.