依据Co-Ni-Sb三元系凝聚态的热力学优化评估和气相组分的热力学数据,利用Thermo-calc软件从热力学角度分析了气相压力对该体系中二元和三元体系的相平衡和相稳定性的影响.结果表明,气相压力减小到一定程度,Co-Ni、Co-Sb、Ni-Sb和Co-Ni-Sb体系中的化合物发生分解,出现气-液-固三相平衡区;计算的三相平衡温度-压力图(T-P图)表明各化合物都存在发生分解的临界压力和临界温度,在临界压力之上或临界温度以下,凝聚相间保持与常压下基本相同的相平衡关系.通过真空条件下Ni/ηCoSb3三元扩散偶测定的Co-Ni-Sb三元系1073 K等温截面,验证了计算的相平衡关系.研究结果为制备含Ni方钴矿热电材料ηCoSb3的工艺设计提供了热力学参考.%According to the assessed and optimized thermodynamic parameters of the condensed phases and those of the gas-phase constituents of the Co-Ni-Sb ternary system,the effect of the gas-phase pressure on the phase equilibria and the phase stability of the binary and ternary systems were analyzed thermodynamically.The re-sults show that the compounds of the Co-Ni,Co-Sb,Ni-Sb and Co-Ni-Sb systems start to pyrolyze when the gas-phase pressure decreases to a certain degree,and the gas-liquid-solid three-phase equilibrium zones appear. The calculated temperature-pressure diagrams (T-P diagram)of the compounds show that each compound has a critical minimum pressure value corresponding to a temperature values for its pyrolysis.Above the minimum pressure or below the temperature,the compound phase can keep the same phase relations as those at the at-mosphere pressure.Through the determination of 1073 K isothermal-section of the Co-Ni-Sb ternary system in vacuum condition by the three ternary diffusion couple Ni/ηCoSb3 ,the calculated Co-Ni-Sb phase equilibria re-lations is tested and verified at 1073 K.The research results supply with the thermodynamical reference for the preparation process design of theηCoSb3 skutterudite compound containing Ni.
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