金属银熔体快冷过程的计算机模拟

Simulation of Molten Ag in the Condition of Rapid Cooling

利用分子动力学模拟技术研究了由周期性边界条件控制的500个银(Ag)原子构成的金属Ag熔体快速冷凝过程.冷却速率为8×1013K/s.模拟在FS(Finnis-Sinclair)相互作用势的基础上,通过双体分布函数、键对分析技术、键取向序等多种方法,对液银快速冷凝过程的微观结构转变特性作了分析,给出了连续快速冷凝过程中液银原子间依靠相互作用力形成的独特的微观结构图像.并考察了冷却过程中体系能量和元胞体积随温度的变化.模拟结果表明在快速冷凝过程中液Ag没有形成bcc结构的倾向.

The dependence of pair distribution function of molten Ag on the temperature under the rapid cool- ing conditions has been researched by molecular dynamics simulation technique. The rapid cooling rate is 8 ×10^13K/s. The proportions of small atom groups of different types have been analyzed by adopting bond pair index method, and the important information of the microstructttre transfer of the system has been obtained. The conclusion has been gained that the bee structure cannot be formed in the cooling process of liquid metal Ag system. The noncrystal is formed under the rapid cooling conditions. The noncrystal is not ＂frozen liquid＂.