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用分子动力学模拟方法研究了冷却速度对银最终构型的影响规律.通过分析银的径向分布函数、HA键对和最大晶体团簇中的原子数,确定出了银凝固后形成非晶的冷却速度.在此基础上,研究了周期性边界条件下银在凝固过程中亚临界晶核和晶体团簇的平衡结构.结果表明:在一定的冷却速度范围内,银熔体凝固后得到的组织是晶体团簇与非晶的混合体,最大晶体团簇尺寸随冷速的增加而减小,当冷速达到一个临界值时,晶体团簇完全消失.银熔体在凝固过程中的晶体团簇及结晶后的晶体是由面心立方和密排六方构成的层状偏聚结构.该层状偏聚结构起源于熔体中的晶胚,在形核阶段就已经生成,并非在生长阶段才开始产生.
The effect of cooling rate on the final configuration of silver was studied by using the molecular dynamics simulation method. By analyzing the silver radial distribution function, the number of HA bond pairs and the number of atoms in the largest crystal cluster, silver was determined to be amorphous The equilibrium structure of subcritical nuclei and crystal clusters during the solidification process was studied.The results show that the solidification of silver melt at a certain cooling rate Of the crystal structure is a mixture of amorphous and crystalline clusters, the largest crystal size decreases with increasing cooling rate, when the cooling rate reaches a critical value, the crystal clusters completely disappear. Silver melt in the solidification process The crystal cluster and the crystallized crystal are layered segregation structures composed of face-centered cubic and close-packed hexagons.The layered segregation structure originates from the embryo in the melt and has been formed during the nucleation stage, Growth stage began to produce.