铜银合金比热的分子动力学模拟

MOLECULAR DYNAMICS SIMULATIONS OF THE HEAT CAPACITY OF Cu-Ag ALLOY

本文采用嵌入原子模型对铜银合金的比热进行了分子动力学模拟，得到了铜银合金从深过冷态到熔点以上温度范围内的比热以及比热随温度的变化规律，并从内聚能的角度分析了铜银合金比热与温度的关系。与已有的铜镍合金的比热随温度变化规律的报道不同，本文的模拟结果和理论分析表明铜银合金的比热在 ８００ Ｋ～１９００ Ｋ的温度范围内基本为一恒值，其过冷液态下的比热可由熔点以上的比热外推得到。

Based on the embedded-atom method (EAM), the heat capacity of Cu-Ag alloy has been simulated with the molecular dynamics simulation. The specific heat of Cu-Ag alloy and its tempera- ture dependence have been obtained. The relationship between the heat capacity and temperature has been analyzed in the viewpoint of cohesive energy. Simulation results and theoretical analyses show that the specific heat of Cu-Ag alloy is approximately constant in the temperature range from 800 K to 1900 K. It means that the heat capacity of Cu-Ag alloy in the Undercooled state can be estimated by extrapolating the heat capacity of Cu-Ag above the melting point, which is different with the heat capacity of subcooled Cu-Ni alloy recerltly reported by the authors.