摘要
采用常温常压分子动力学模拟技术,模拟了液态Ni3Al中原子团簇在快速凝固条件下的演变过程,模型采用的是TB(tight-binding)作用势.用偶分布函数、键对和多面体等结构参数来描述快速凝固条件下团簇种类和数量的变化,并将团簇结构可视化.在2000K下,液态Ni3Al中团簇数量较少,且都是由缺陷二十面体构成;在4×1013K·S-1的冷速下,团族的数量随温度的降低不断增加,且出现完整二十面体团簇,体系最终形成了由二十面体和缺陷二十面体团簇网络所组成的非晶结构.
Aseries of simulation of the evoluti on of atom clusters in liquid Ni 3 Al alloy during rapid solidifica-tion have been performed under constant pressure and temperature by mole cular dynamic simulation technique.TB(tight -binding)potential function has been adopted to describe the interaction between atoms.The structure pa-rameters such as pair correlation fu nction,bonded pairs and polyhedra c lusters have been used to characterize the dependence of the type and number of c lusters on temperature during rapid cooling process.The cluster structure could be visualized clearly through the conversion of atom coordinates o btained by simulation to three -dime nsion graphical interface.The number of l iquid Ni 3 Al clusters at the temperature of 2000Kis small and all are made up of diicosahedron;however,it incre ases rapidly at the cooling rate of 4×1013K·s-1,and finally,the icosahedra clusters occur at low temperature.T he network consists of the icosahedr a and diicosahedra clusters forming an amorphous system.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2002年第4期297-301,共5页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(50071028)资助项目
