The phase equilibria of the Cu-Nb-Ni system were investigated via a combination of key equilibrated alloys and thermodynamic modeling. Twelve different compositions of ternary alloys were prepared to determine the isothermal sections at 700, 800 and 900 °C, by means of x-ray diffraction and scanning electron microscopy with energy dispersive x-ray spectroscopy. The three- and two-phase regions were determined. The solubilities of the NbNi₃ and Nb₇Ni₆ phases were measured. No ternary compound was found in this ternary system. Based on the experimental equilibria data from the literature and the present work, a thermodynamic description of the Cu-Nb-Ni system was carried out by using the CALPHAD (CALculation of PHAse Diagrams) method. The substitutional model and sublattice model were employed to describe the solution phases and intermediate phases, respectively. A set of self-consistent thermodynamic parameters of the Cu-Nb-Ni system was conclusively obtained. Most of the reliable experimental data were reproduced by the present thermodynamic modeling.

通过关键平衡合金和热力学模型的组合研究了Cu-Nb-Ni体系的相平衡。通过X射线衍射和具有能量色散X射线光谱的扫描电子显微镜，制备了十二种不同的三元合金成分，以确定在700、800和900°C下的等温截面。确定了三相和两相区域。NbNi ₃和Nb ₇ Ni ₆的溶解度测量相位。在该三元体系中未发现三元化合物。基于来自文献的实验平衡数据和当前工作，使用CALPHAD（PHHAse图的计算）方法对Cu-Nb-Ni体系进行了热力学描述。用替代模型和亚晶格模型分别描述了固溶相和中间相。结论性地获得了一组Cu-Nb-Ni体系的自洽热力学参数。通过当前的热力学模型可以再现大多数可靠的实验数据。