【作者】 周丽丽； 刘让苏； 田泽安； 刘全慧；

【Author】 ZHOU Li-li~(1,2),LIU Rang-su~1,TIAN Ze-an~1,LIU Quan-hui~1 (1.School of Physics and Microelectronics Science,Hunan University,Changsha 410082,China; 2.Department of Information Engineering,Gannan Medical University,Ganzhou 341000,China)

【机构】 湖南大学物理与微电子科学学院； 赣南医学院信息工程学院；

【摘要】 采用分子动力学方法对两种不同冷却速率对液态Ca₇Mg₃合金快速凝固过程中纳米结构演变的影响进行了模拟研究。采用Honeycutt-Andersen键型指数法、原子团类型指数法、可视化分析等方法对凝固过程中微观团簇结构演变进行了分析。结果表明,系统的玻璃转变温度随冷速的升高而升高;（12 0 120）二十面体基本原子团对系统非晶态结构的形成起到了主导作用,这些二十面体基本原子团相互交织成网络状分布在系统中。同时发现,冷速对系统凝固结构的影响在773K以下才开始表现出来,冷速越低,系统中所形成的二十面体基本原子团越多,系统越容易形成大尺寸的纳米级团簇结构。更多还原

【Abstract】 A molecular dynamics simulation study was performed for the cooling rate effects on the microstruc-ture evolution during the rapid solidification process.The bond-type index method of Honeycutt-Andersen (HA),the cluster type index method(CTIM),and the visual analysis method have been used to analyze the e-volution of micro-structures during the solidification.The results shows that the higher cooling rate corresponding to a higher glass transition temperature;moreover,the(12 0 12 0) icosahedron basic clusters plays a key role on the formation of the amorphous structure,they are inter-percolated into each other and form a network in the system;it has also been found that the cooling rate effects on the solidification structure only shows up bellows 773 K,the smaller the cooling rate is,the more icosahedron basic clusters form,and the more easy of the big size nano-cluster to form in the system.更多还原