The accurate interdiffusivity for fcc_A1 Ni–Cr–V system is needed for simulating the microstructure evolution for Ni-based alloys. In order to determine the interdiffusivity, totally fifteen diffusion couples bound with fcc_A1 Ni–Cr–V alloys were prepared in the present work. Both EPMA (Electron Probe Micro-Analysis) and XRD (X-ray diffraction) results can verify that all the samples are of fcc_A1 single phase. The composition profiles of each diffusion couple annealed at 1273, 1373 and 1473 K were measured by EPMA and then were fitted by Boltzmann function. Applied the fitted composition profiles to Matano-Kirkaldy method, the interdiffusivities at the intersection points of every two diffusion paths were obtained. All of the obtained interdiffusivities can satisfy the constraints of the thermodynamic stability. Moreover, in order to obtain the composition-dependent interdiffusivity, two types of the numerical inverse method implemented in a recently developed CALTPP (CALculation of ThermoPhysical Properties) program were utilized in the present work. Both methods can result in consistent composition profiles in comparison with the measured ones and can produce interdiffusivities in good agreements with the ones by Matano-Kirkaldy method. Both methods have advantages which can be selected flexibly. In the present work, the pure mathematical method was recommended due to its higher accuracy.

fcc_A1 Ni–Cr–V系统的准确互扩散系数是模拟Ni基合金微观组织演变所必需的。为了确定相互扩散性，在本工作中准备了总共15个与fcc_A1 Ni–Cr–V合金结合的扩散偶。EPMA（电子探针微分析）和XRD（X射线衍射）结果均可验证所有样品均为fcc_A1单相。通过EPMA测量在1273、1373和1473 K下退火的每个扩散对的组成分布，然后通过玻尔兹曼函数进行拟合。将拟合的成分分布图应用于Matano-Kirkaldy方法，获得每两个扩散路径的交点处的互扩散性。所有获得的互扩散性都可以满足热力学稳定性的约束。此外，为了获得取决于成分的互扩散性，在本工作中使用了在最近开发的CALTPP（热物理性质计算）程序中实现的两种类型的数值逆方法。两种方法都可以得到与被测方法相比一致的组成曲线，并且可以通过Matano-Kirkaldy方法与它们产生良好的相互扩散性。两种方法都具有可以灵活选择的优点。在目前的工作中，由于其较高的准确性而推荐使用纯数学方法。两种方法都可以得到与被测方法相比一致的组成曲线，并且可以通过Matano-Kirkaldy方法与它们产生良好的相互扩散性。两种方法都具有可以灵活选择的优点。在目前的工作中，由于其较高的准确性而推荐使用纯数学方法。两种方法都可以得到与被测方法相比一致的组成曲线，并且可以通过Matano-Kirkaldy方法与它们产生良好的相互扩散性。两种方法都具有可以灵活选择的优点。在目前的工作中，由于其较高的准确性而推荐使用纯数学方法。