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采用普适的嵌入原子模型模拟Pb30Ag70,Pb40Ag60和Pb60Ag403种合金体系的升温过程,用于计算合金体系的微观及宏观性质,首先模拟298~1498 K时体系的生成焓,进而得到不同温度下合金体系生成自由能和过剩自由能,Pb30Ag70,Pb40Ag60和Pb60Ag403种合金的过剩自由能分别为1.26,1.66和1.90 kJ,与实验值符合较好,3种合金的过剩自由能均为正值,合金中原子间平均相互作用较小。同时计算合金的结合能及形成能等能量函数,计算得到Pb-Ag合金的结合能随温度升高不断降低,即合金中原子间平均相互作用不断降低。Pb-Ag合金的形成能为正值,表明合金为正偏差体系,随着温度的升高,合金形成能的绝对值不断降低趋近于0,可以判断合金与理想熔体间的偏离程度不断降低,合金体系趋近于理想熔体,合金中Pb含量越大,合金与理想熔体的偏离程度越小,通过对形成能的计算可以定量的判断合金与理想熔体的偏离程度。
The universal embedded atomic model is used to simulate the temperature rising process of Pb30Ag70, Pb40Ag60 and Pb60Ag403 alloy systems and to calculate the microscopic and macroscopic properties of the alloy system. First, the enthalpies of formation at 298 ~ 1498 K are simulated, then the alloy system The excess free energy of Pb30Ag70, Pb40Ag60 and Pb60Ag403 alloys are 1.26, 1.66 and 1.90 kJ respectively, which is in good agreement with the experimental data. The excess free energy of the three alloys are all positive. The average interaction between the smaller. At the same time, the binding energies and energy functions of the alloys were calculated, and the binding energies of the Pb-Ag alloys were calculated to decrease with increasing temperature, that is, the average interactions between the atoms in the alloys decreased continuously. The formation of Pb-Ag alloy can be positive, indicating that the alloy is a positive deviation system, as the temperature increases, the absolute value of the alloy forming energy decreases to 0, can determine the degree of deviation between the alloy and the ideal melt The alloy system approaches the ideal melt. The larger the content of Pb in the alloy is, the smaller the deviation between the alloy and the ideal melt is. The calculation of the formation energy can quantitatively determine the deviation of the alloy from the ideal melt.