深过冷液态Ni_2TiAl合金热物理性质的分子动力学模拟

A molecular dynamics simulation of thermodynamic properties of undercooled liquid Ni_2TiAl alloy

采用嵌入原子法对深过冷条件下Ni2TiAl合金的焓和密度进行了分子动力学模拟,模拟获得了比热和密度在1200K至2000K范围内的温度依赖关系.结果表明过冷条件下Ni2TiAl合金的比热、密度和温度之间存在着线性关系,它们都随着温度的降低而降低.比热的大小与依据Neumann-Kopp法则估算的结果相近,同时模拟过程中的尺度效应经验证可以忽略.

Base on the embedded-atom method, the enthalpy and the density of Ni2TiAl alloy are calculated by using molecular dynamics simulations. The temperature dependence of the specific heat of normal and undercooled liquid Ni2TiAl alloy is obtained. The results indicate that the specific heat and the density increase linearly with the decrease of temperature, and the Neumann-Kopp rule can be applied to estimate the specific heat of undercooled liquid Ni2 TiAl alloy. Meanwhile, the size effect in the simulation domain is indicated to be negligible.