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| 液态Ca70Mg30合金快速凝固过程中纳米团簇结构形成演变特性模拟 | |
| 引用本文： | 周丽丽,刘让苏,田泽安.液态Ca70Mg30合金快速凝固过程中纳米团簇结构形成演变特性模拟[J].中国有色金属学会会刊,2013,23(8):2354-2360. |
| 作者姓名： | 周丽丽 刘让苏 田泽安 |
| 作者单位： | 1. 赣南医学院 信息工程学院，赣州 341000; 湖南大学 物理与微电子科学学院，长沙 410082 2. 湖南大学 物理与微电子科学学院,长沙,410082 3. 湖南大学 物理与微电子科学学院，长沙 410082; School of Materials Science and Engineering，University of New South Wales，Sydney NSW 2052，Australia |
| 摘 要： | 采用分子动力学方法对液态Ca70Mg30合金快速凝固过程中纳米团簇结构的形成和演变特性进行模拟。采用原子团类型指数法(CTIM)对凝固过程中纳米团簇结构的演变进行分析。结果表明：系统在5×1011 K/s的冷速条件下形成以1551、1541和1431为主的非晶态结构，非晶转变温度约为530 K；(120120)二十面体基本原子团对系统非晶结构的形成起到决定性的作用，并且原子半径较小的Mg原子更容易占据二十面体基本原子团中心原子的位置；同时，纳米团簇主要是通过中等尺寸团簇的合并而形成，纳米级大团簇的形成演变过程呈现出类似于非晶晶化过程的3个阶段式的变化。 |
| 关 键 词： | 纳米团簇 Ca70Mg30合金 快速凝固 分子动力学模拟 |
| 收稿时间： | 17 July 2012 |
Simulation of formation and evolution of nano-clusters during rapid solidification of liquid Ca70Mg30 alloy |
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| Li-li ZHOU,Rang-su LIU,Ze-an TIAN.Simulation of formation and evolution of nano-clusters during rapid solidification of liquid Ca70Mg30 alloy[J].Transactions of Nonferrous Metals Society of China,2013,23(8):2354-2360. | |
| Authors: | Li-li ZHOU Rang-su LIU Ze-an TIAN |
| Affiliation: | 1. Department of Information Engineering, Gannan Medical University, Ganzhou 341000, China;2. School of Physics and Microelectronics Science, Hunan University, Changsha 410082, China;3. School of Materials Science and Engineering, University of New South Wales, Sydney NSW 2052, Australia |
| Abstract: | A molecular dynamics simulation study was performed to investigate the formation and evolution mechanisms of nano-clusters during the rapid solidification of liquid Ca70Mg30 alloy. The cluster-type index method (CTIM) was adopted to describe microstructure evolutions of nano-clusters during solidification. Results indicate that amorphous structure is mainly formed with three bond-types of 1551, 1541 and 1431 at the cooling rate of 5×1011 K/s, and glass transition temperature Tg is about 530 K; the icosahedron cluster of (12 0 12 0) plays a key role in formation of amorphous structure, and smaller Mg atoms are much more probable to be central atoms of icosahedron clusters; and nano-clusters are mainly formed by combining medium-size clusters. Interestingly, it was also found that formation and evolution processes of the nano-cluster display a three-stage feature which is analogous to crystallization process of amorphous alloy. |
| Keywords: | nano-clusters Ca70Mg30 alloy rapid solidification molecular dynamics simulation |
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