Abstract

The enthalpies of mixing of Ni–Ln NiPr melts (0 < x_Ni < 0.6) are studied via isoperibol calorimetry at 1600 ± 1 K. The enthalpies of mixing for Ni–Pr melts are characterized by high exothermic values. The minimum enthalpy of mixing for the melts of the considered system is −35.3 ± 0.9 kJ/mol at x_Ni = 0.6. The activities of the components and the molar fractions of the most stable associates in melts of the Ni–Pr system are estimated using the model of ideal associated solutions (IAS). Literature data (enthalpies of formation of Pr_mNi_n compounds, phase diagram of the Ni–Pr system) and the obtained thermochemical data are both used. Five associates are selected for calculations. It is shown that the activities of the components in the melts of this system display large negative deviations from Raoult’s law, and the PrNi₂ associate predominates in them.

中文翻译：

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Ni-Pr 合金的相平衡和热力学

摘要

Ni-Ln NiPr 熔体的混合焓 (0 < x _Ni < 0.6) 通过等周波量热法在 1600 ± 1 K 下进行研究。 Ni-Pr 熔体的混合焓以高放热值为特征。在x _Ni = 0.6 时，所考虑系统的熔体的最小混合焓为 -35.3 ± 0.9 kJ/mol 。使用理想相关溶液 (IAS) 模型估算 Ni-Pr 系统熔体中最稳定缔合物的组分的活性和摩尔分数。文献数据（Pr _m Ni _n的形成焓化合物，Ni-Pr 系统的相图）和获得的热化学数据都被使用。选择了五名同事进行计算。结果表明，该系统熔体中组分的活性与拉乌尔定律有很大的负偏差，其中 PrNi ₂缔合物占主导地位。