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采用分子动力学方法和Quantum Sutton-Chen(QS-C)多体势,对液态金属铜(Cu)凝固过程中的晶体生长规律及纳米团簇微观结构转变特性进行了模拟跟踪研究.运用Honeycutt-Andersen(HA)键型指数法和新的原子团类型指数法(CTIM-2)分析了金属Cu原子的成键类型和原子团簇结构演变特性.结果发现:当以1.0×10~(13)K/s速率凝固时,系统最终形成晶体和非晶体混合共存结构;在以4.0×10~(12) K/s速度冷却时,系统从673 K就开始结晶,并形成以1421和1422二种键型为主的晶体结构;面心立方(FCC)和六角密集(HCP)结构在形成晶体铜时起着非常重要的作用,尤其是由1421键型构成的面心立方(12000120)基本原子团在晶体生长和纳米团簇结构形成过程中占主导地位.
The crystal growth law and the microstructure transition characteristics of nanoclusters during the solidification of liquid copper (Cu) were investigated by molecular dynamics method and Quantum Sutton-Chen (QS-C) multi-body potential. The honeycutt- Andersen (HA) bond index method and a new atomic group index method (CTIM-2) were used to analyze the bonding type and atomic cluster structure evolution characteristics of Cu atoms. The results showed that when the crystal structure was characterized by 1.0 × 10 13 K / s, the system finally formed a coexisting crystal and amorphous structure. At cooling rate of 4.0 × 10 ~ (12) K / s, the system began to crystallize from 673 K and formed two kinds of bonds of 1421 and 1422 (FCC) and hexagonal dense (HCP) structures play a very important role in the formation of crystalline copper. In particular, the face-centered cubic (12000120) fundamental atomic group consisting of the 1421 bond forms a crystal structure during crystal growth And the formation of nano-cluster structure dominates.