计算机模拟研究NiAl合金的平衡结构

DETERMINATION OF NiAl STABLE STRUCTURESFROM COMPUTER SIMULATIONS

利用嵌入原子类型的势函数，通过MonteCarlo模拟研究了极低温条件下NiAl合金的稳定结构，发现点阵参数c／a约为1．315的bct结构是稳定结构，B2结构是1种正稳结构．在此基础上，通过分子动力学模拟分析了系统内应力随点阵参数的变化关系，分别计算了若干温度下B2和bct结构NiAl合金的平衡点阵参数。随着温度的升高，点阵参数逐渐增加，但bct结构的c／a值基本不变。

The Monte Carlo simulations with the embedded-atom type potential wereperformed to determine the stable structures of the NiAl alloy at very low temperatures. Thebet structure, with a ratio of lattice contants c/a of about 1.315, is found to be stable', while B2structure is metastable. The lattice contants of the stoichiometric NiAl alloy with B2 and betstructures were calculated at different temperatures, by analyzing the relationship betweenthe internal stresses and the lattice parameters from the molecular dynamics simulations.The values of the lattice contants increase when the temperature increased, while the c/aratio of the bet structure keeps almost constant.