Department of Materials Science and Engineering, Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
Sandvik Coromant R&D, SE-126 80, Stockholm, Sweden.
J Chem Phys. 2018 Jun 28;148(24):244503. doi: 10.1063/1.5026348.
Self- and impurity diffusion coefficients are assessed in the liquid nickel system by the fundamental ab initio molecular dynamics approach. The impurity diffusion coefficients in the Ni-X systems (X=C, Co, N, Nb, Ta, Ti, W) are mostly not available in the current literature. The simulations are performed at four temperatures, in the range from 1903 to 2303 K, which allows to extract activation energies and frequency factors for the temperature dependent diffusion coefficient assuming an Arrhenius-type behavior in the liquid. In addition to the temperature dependence, the concentration-dependent impurity diffusion was investigated for the Ni-Co system. The data are of relevance for the development of the state-of-the art Ni-based superalloys and alternative binder systems in cemented carbides. The obtained theoretical results are in very good agreement with the limited experimental data for the diffusion in liquid Ni systems.
通过基本的从头分子动力学方法评估了液体镍体系中的自扩散系数和杂质扩散系数。目前文献中大多没有 Ni-X 体系（X=C、Co、N、Nb、Ta、Ti、W）中杂质的扩散系数。模拟在四个温度下进行，范围从 1903 到 2303 K，这允许在液体中假设 Arrhenius 型行为来提取与温度相关的扩散系数的激活能和频率因子。除了温度依赖性外，还研究了 Ni-Co 体系中浓度依赖性的杂质扩散。这些数据对于开发先进的基于 Ni 的高温合金和硬质合金中替代粘结剂系统具有重要意义。获得的理论结果与液体 Ni 体系中扩散的有限实验数据非常吻合。
