Effect of local structures on crystallization in deeply undercooled metallic glass-forming liquids
- International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871 (China)
The crystallization mechanism in deeply undercooled ZrCu metallic glass-forming liquids was investigated via molecular dynamics simulations. It was found that the crystallization process is mainly controlled by the growth of crystal nuclei formed by the BCC-like atomic clusters, consistent with experimental speculations. The crystallization rate is found to relate to the number of growing crystal nuclei in the crystallization process. The crystallization rate in systems with more crystal nuclei is significantly hindered by the larger surface fractions of crystal nuclei and their different crystalline orientations. It is further revealed that in the crystallization in deeply undercooled regions, the BCC-like crystal nuclei are formed from the inside of the precursors formed by the FCC-like atomic clusters, and growing at the expense of the precursors. Meanwhile, the precursors are expanding at the expense of the outside atomic clusters. This process is consistent with the so-called Ostwald step rule. The atomic structures of metallic glasses are found to have significant impact on the subsequent crystallization process. In the Zr{sub 85}Cu{sub 15} system, the stronger spatial correlation of Cu atoms could hinder the crystallization processes in deeply undercooled regions.
- OSTI ID:
- 22660851
- Journal Information:
- Journal of Chemical Physics, Vol. 144, Issue 15; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
Similar Records
Growth mechanism from nano-ordered clusters to nanocrystals in a deeply undercooled melt of Zr-Ni-Ti metallic glass
Thermodynamic prediction of glass formation tendency, cluster-in-jellium model for metallic glasses, ab initio tight-binding calculations, and new density functional theory development for systems with strong electron correlation