The liquidus surface projection and isothermal sections at 1200 and 1000 °C of the Fe-Ni-Ta system were established by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectrometry (EDS) and x-ray diffraction (XRD). Eight primary solidification regions in the liquidus surface projection were experimentally obtained. The similar phase relations were derived in the isothermal sections at 1200 and 1000 °C. Based on the experimental results in the present work and reported in the literature, the Fe-Ni-Ta system was optimized by means of CALPHAD (CALculation of PHAse Diagram) method. Solution phases (liquid, fcc, bcc) were treated as the substitutional solution. The compounds Fe 2 Ta, Ni 2 Ta, Ni 3 Ta and NiTa 2 were treated as (Fe,Ni,Ta) m (Fe,Ni,Ta) n by a two-sublattice model, and (Fe,Ni) 7 Ta 6 was modelled as (Fe,Ni,Ta) 1 (Ta) 4 (Fe,Ni,Ta) 2 (Fe,Ni,Ta) 6 by a four-sublattice model. A set of self-consistent thermodynamic parameters for the Fe-Ni-Ta system was acquired.

中文翻译：

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Fe-Ni-Ta 系统的实验研究和热力学建模

通过扫描电子显微镜 (SEM) 结合能谱仪 (EDS) 和 X 射线衍射 (XRD) 建立了 Fe-Ni-Ta 系统在 1200 和 1000 °C 的液相线表面投影和等温截面。通过实验获得液相线表面投影中的八个主要凝固区域。在 1200 和 1000 °C 的等温截面中导出了类似的相关系。基于目前工作中的实验结果和文献报道，Fe-Ni-Ta 系统通过 CALPHAD (CALculation of PHAse Diagram) 方法进行了优化。溶液相（液体、fcc、bcc）被视为替代溶液。化合物 Fe 2 Ta, Ni 2 Ta, Ni 3 Ta 和 NiTa 2 通过二亚晶格模型处理为 (Fe,Ni,Ta) m (Fe,Ni,Ta) n 和 (Fe,Ni) 7 Ta 6 被建模为 (Fe,Ni, Ta) 1 (Ta) 4 (Fe,Ni,Ta) 2 (Fe,Ni,Ta) 6 四亚晶格模型。获得了一组用于 Fe-Ni-Ta 系统的自洽热力学参数。