Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (02): 245-249.doi: 10.3866/PKU.WHXB201212251

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Solidification of Liquid Fe with Embedded Homogeneous Solid Fe Nanoparticles from Molecular Dynamics Simulations

WU Yong-Quan, SHEN Tong, LU Xiu-Ming, ZHANG Ning, LAI Li-Shan, GAO Shuai   

  1. Solidification processes of liquid Fe with embedded homogeneous solid nanoparticle with radius ranging from 0.4 to 1.8 nm were studied by molecular dynamics (MD) simulation adopting the Sutton-Chen potential. It was found that the particles whose radii exceed 0.82 nm could obviously decrease the critical undercooling (ΔT*) and induce solidification. The microstructural evolution during the solidification process was traced through the atom definition with cluster-type index method (CTIM-2). Results revealed that when the embedded particle induced solidification, the growth process of nucleus would proceed as a cross-nucleation between hcp and fcc structures, a little similar to the eutectic crystallization process. Moreover, the heredity effect attributed by embedded solid nanoparticle was clearly observed during the microstructural evolution.
  • Received:2012-12-03 Revised:2012-12-25 Published:2013-01-14
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2012CB722805), National Natural Science Foundation of China (50504010, 50974083, 51174131), Joint Funds of ational Natural Science Foundation of China-Steel, China (50774112), Shanghai “Phosphor” Science Foundation, China (07QA4021 ).

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Abstract:

Solidification processes of liquid Fe with embedded homogeneous solid nanoparticle whose radius ranges from 0.4 to 1.8 nm have been studied by molecular dynamics simulation adopting the Sutton-Chen potential. It was found that the particles whose radii exceed 0.82 nm can obviously decrease the critical undercooling (ΔT*) and induce solidification. The microstructural evolution during the solidification process is traced through the atom definition with cluster-type index method (CTIM-2). Results revealed that when the embedded particle induced solidification, the growth process of nucleus would proceed as a cross-nucleation between hcp and fcc structures, a little similar to the eutectic crystallization process. Moreover, the heredity effect attributed by embedded solid nanoparticle is clearly observed during the microstructural evolution.

Key words: Solid Fe nanoparticle, Undercooling, Solidification process, Microstructural evolution, Molecular dynamics simulation