Formation mechanism of atomic cluster structures in Al-Mg alloy during rapid solidification processes
- School of Physics and Microelectronics Science, Hunan University, Changsha, Hunan Province 410082 (China)
- Department of Applied Physics, Chang'an University, Xi'an 710064 (China)
- College of Materials Science and Engineering, Hunan University, Changsha 410082 (China)
The rapid solidification processes of Al{sub 50}Mg{sub 50} liquid alloy consisting of 50,000 atoms have been simulated by using molecular dynamics method based on the effective pair potential derived from the pseudopotential theory. The formation mechanisms of atomic clusters during the rapid solidification processes have been investigated adopting a new cluster description method-cluster-type index method (CTIM). The simulated partial structure factors are in good agreement with the experimental results. And Al-Mg amorphous structure characterized with Al-centered icosahedral topological short-range order (SRO) is found to form during the rapid solidification processes. The icosahedral cluster plays a key role in the microstructure transition. Besides, it is also found that the size distribution of various clusters in the system presents a magic number sequence of 13, 19, 23, 25, 29, 31, 33, 37, .... The magic clusters are more stable and mainly correspond to the incompact arrangements of linked icosahedra in the form of rings, chains or dendrites. And each magic number point stands correspondingly for one certain combining form of icosahedra. This magic number sequence is different from that generated in the solidification structure of liquid Al and those obtained by methods of gaseous deposition and ionic spray, etc.
- OSTI ID:
- 21167711
- Journal Information:
- Annals of Physics (New York), Vol. 324, Issue 2; Other Information: DOI: 10.1016/j.aop.2008.10.010; PII: S0003-4916(08)00165-6; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-4916
- Country of Publication:
- United States
- Language:
- English
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