Thermodynamic calculation of phase equilibria of rare earth metals with boron binary systems
Thermodynamic calculation of phase equilibria of rare earth metals with boron binary systems
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DOI：
10.1515/ijmr-2021-8340
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发表时间：
2022-01
影响因子：
0.8
通讯作者：
Qi Wei;M. Rong;Sha Li;D. Su;Q. Yao;Jiang Wang;Qing Chen;G. Rao;Huai-ying Zhou
中科院分区：
文献类型：
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作者：
Qi Wei;M. Rong;Sha Li;D. Su;Q. Yao;Jiang Wang;Qing Chen;G. Rao;Huai-ying Zhou
摘要为了开发稀土硼化物和过渡金属的新型材料，稀土硼合金的相平衡和热力学信息是必不可少的。在实验相平衡和热力学性质的基础上，用相图计算（CALPHAD）方法对RE-B（RE = La，Sm，Gd和Tb）二元系进行了热力学计算。得到了RE-B（RE = La，Sm，Gd和Tb）二元系的自洽参数，该参数能较好地再现实验数据。结合文献中对RE-B二元系的评价，系统地讨论了RE-B（RE = La，Ce，Pr，Nd，Sm，Gd，Tb，Dy，Ho，Er，Tm和Lu）二元系的相平衡和热力学性质。结果表明，相平衡和热力学信息随稀土原子序数的变化趋势。随着稀土原子序数的增加（La、Ce、Pr和Nd除外），液态稀土-硼合金的混合焓和稀土-硼金属间化合物的生成焓逐渐变负，而稀土-硼金属间化合物的相变温度逐渐升高。
Abstract In order to develop novel materials based on rare earth (RE) boride and/or transition metals, phase equilibria and thermodynamic information of the RE–B based alloys are indispensable. On the basis of experimental phase equilibria and thermodynamic properties, thermodynamic assessments of the RE–B (RE = La, Sm, Gd and Tb) binary systems were carried out by the CALPHAD (Calculation of Phase Diagram) method. Self-consistent parameters of the RE–B (RE = La, Sm, Gd and Tb) binary systems were obtained, which can be used to reproduce well the experimental data. Furthermore, in combination with the previous assessments of the RE–B binary systems in the literature, phase equilibria and thermodynamic properties of the RE–B (RE = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm and Lu) binary systems are discussed systematically. The tendency of phase equilibria and thermodynamic information as a function of RE atomic number is demonstrated. In general, the enthalpy of mixing of liquid RE–B alloys and the enthalpy of formation of the RE–B intermetallic compounds become more and more negative with the increase in RE atomic number (except for La, Ce, Pr and Nd), while the phase transition temperatures for the RE–B intermetallic compounds increase gradually.