初始条件对Ga冷凝过程影响的模拟研究

Simulation Study of Microstructure Transition of Liquid Metals Ga during the Different Initial Conditions

对液态金属快速凝固过程进行了分子动力学模拟研究.以1000个液态纯金属Ga原子的系统为例,深入考察了微观结构组态的变化.采用H-A键型指数法分析该过程中各种键的变化情况.发现在其微观结构的转变过程中,与二十面体及其缺陷结构密切相关的1551键型起着重要的作用,同时,还发现不同的初始平衡态对其固态微结构有明显的影响,这一结果对于深入理解液-固微结构之间的转变关系,具有一定的理论和实际意义.

<Abstrcat> Molecular dynamics simulation study has been performed for a liquid metal system consisting of 1000 Ga atoms to deeply investigate the transition of microstructure configurations. To describe the changes of the atomic bond-types in the liquid system, the new cluster-type index and Honeycutt-Andersen index has been used. It has been found that during the microstructure transition processes the forming of icosahedra and its defective structures related to the 1551 bond-type play an important role. Furthermore, we can obtain that different initial conditions of liquid metal Ga have remarkable effects on the solidification microstructures during the same rapid solidification process. The results will give us a new way to understand the microstructure transitions of liquid metals from liquid to solid states.