Ni_(50)Al_(50)合金的液固转变及晶体生长过程的分子动力学模拟

Atomic simulation of amorphization and crystallization of Ni_(50)Al_(50) and its crystal growth process

采用分子动力学模拟技术研究了液态Ni50 Al50 合金在不同冷速下的凝固特点 ,模拟采用EAM作用势 ,计算了不同温度 ,不同冷速下Ni50 Al50 的偶分布函数。结果表明EAM作用势能很好地描述液态Ni50 Al50 的无序结构 ,在快速凝固条件下 ,液态Ni50 Al50 形成非晶 ,当冷速较慢时 ,液态Ni50 Al50 形成晶体 ,分析了不同冷速下体系的相变热力学及相变动力学特点。最后采用液固两层构型法 ,清楚地观察到Ni50 Al50 晶体生长的全过程。

By means of the molecular dynamic simulation technique, pair distribution functions of liquid Ni 50 Al 50 during different cooling and temperature have been simulated. EAM was used as many body interaction. The finding indicates that EAM can describe the liquid system of Ni 50 Al 50 well; molten Ni 50 Al 50 will form the crystal with the relatively solw cooling rate, and the glass transition of Ni 50 Al 50 will be performed with relatively rapid cooling rate. The thermodynamics and kinetics of structure transition of Ni 50 Al 50 during cooling processes have been performed; the crystal growth of Ni 50 Al 50 has been studied using crystal liquid configuration method lastly.