中国物理B ›› 2007, Vol. 16 ›› Issue (12): 3747-3753.doi: 10.1088/1009-1963/16/12/032

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A simulation study of microstructure evolution during solidification process of liquid metal Ni

刘海蓉1, 张爱龙1, 刘让苏2, 侯兆阳2, 王 鑫2, 田泽安2   

  1. (1)College of Materials Science and Chemical Engineering, Hunan University, Changsha 410082, China; (2)Department of Physics, Hunan University, Changsha 410082, China
  • 出版日期:2007-12-20 发布日期:2007-12-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 50271026 and 50571037).

A simulation study of microstructure evolution during solidification process of liquid metal Ni

Liu Hai-Rong(刘海蓉)a), Liu Rang-Su(刘让苏)b)†, Zhang Ai-Long(张爱龙)a), Hou Zhao-Yang(侯兆阳)b), Wang Xin(王鑫)b), and Tian Ze-An(田泽安)b)   

  1. a College of Materials Science and Chemical Engineering, Hunan University, Changsha 410082, China; b Department of Physics, Hunan University, Changsha 410082, China
  • Online:2007-12-20 Published:2007-12-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 50271026 and 50571037).

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摘要： A molecular dynamics simulation study has been performed for the microstructure evolution in a liquid metal Ni system during crystallization process at two cooling rates by adopting the embedded atom method (EAM) model potential. The bond-type index method of Honeycutt--Andersen (HA) and a new cluster-type index method (CTIM-2) have been used to detect and analyse the microstructures in this system. It is demonstrated that the cooling rate plays a critical role in the microstructure evolution: below the crystallization temperature $T_{\rm c}$, the effects of cooling rate are very remarkable and can be fully displayed. At different cooling rates of $2.0\times10^{13}$\,K\,$\cdot$\,s$^{-1}$ and $1.0\times10^{12}$\,K\,$\cdot$\,s$^{-1}$, two different kinds of crystal structures are obtained in the system. The first one is the coexistence of the hcp (expressed by (12 0 0 0 6 6) in CTIM-2) and the fcc (12 0 0 0 12 0) basic clusters consisting of 1421 and 1422 bond-types, and the hcp basic cluster becomes the dominant one with decreasing temperature, the second one is mainly the fcc (12 0 0 0 12 0) basic clusters consisting of 1421 bond-type, and their crystallization temperatures $T_{\rm c}$ would be 1073 and 1173\,K, respectively.

关键词: liquid metal Ni, cooling rate, crystallization process, microstructure evolution, molecular dynamics simulation

Abstract: A molecular dynamics simulation study has been performed for the microstructure evolution in a liquid metal Ni system during crystallization process at two cooling rates by adopting the embedded atom method (EAM) model potential. The bond-type index method of Honeycutt--Andersen (HA) and a new cluster-type index method (CTIM-2) have been used to detect and analyse the microstructures in this system. It is demonstrated that the cooling rate plays a critical role in the microstructure evolution: below the crystallization temperature $T_{\rm c}$, the effects of cooling rate are very remarkable and can be fully displayed. At different cooling rates of $2.0\times10^{13}$ K $\cdot$ s$^{-1}$ and $1.0\times10^{12}$ K $\cdot$ s$^{-1}$, two different kinds of crystal structures are obtained in the system. The first one is the coexistence of the hcp (expressed by (12 0 0 0 6 6) in CTIM-2) and the fcc (12 0 0 0 12 0) basic clusters consisting of 1421 and 1422 bond-types, and the hcp basic cluster becomes the dominant one with decreasing temperature, the second one is mainly the fcc (12 0 0 0 12 0) basic clusters consisting of 1421 bond-type, and their crystallization temperatures $T_{\rm c}$ would be 1073 and 1173 K, respectively.

Key words: liquid metal Ni, cooling rate, crystallization process, microstructure evolution, molecular dynamics simulation

中图分类号:  (Computer simulation of liquid structure)

  • 61.20.Ja
61.25.Mv (Liquid metals and alloys) 64.70.D- (Solid-liquid transitions)