In this study, we utilized a quantitative atomistic analysis approach to investigate the impact of chemical ordering structures on the diffusion behavior of interstitials and vacancies within the CrCoNi medium entropy alloy (MEA), employing an advanced neural network interatomic potential (NNP). We discovered that the degree of chemical ordering, which can be precisely controlled through annealing at elevated temperatures, significantly influences both interstitial and vacancy diffusion. This phenomenon contributes to the notable sluggish diffusion characteristic of CrCoNi, largely attributable to the restriction of diffusion pathways in regions with lower degree of chemical ordering. We also emphasized the crucial role of operating temperature on diffusion, which should be remained well below the annealing temperature to preserve the sluggish diffusion effect. Our research sheds light on the interplay between chemical ordering and defect diffusion in MEAs, and it proposes effective strategies for tailoring the diffusivity of MEAs by altering their chemical ordering. These insights are instrumental in the development of next-generation materials, which are optimized for use in challenging environments, such as high-temperature and irradiation conditions.

在本研究中，我们采用定量原子分析方法，采用先进的神经网络原子间势（NNP），研究化学有序结构对 CrCoNi 中熵合金（MEA）内填隙和空位扩散行为的影响。我们发现，可以通过高温退火精确控制的化学有序程度显着影响间隙和空位扩散。这种现象导致了 CrCoNi 显着的缓慢扩散特性，很大程度上归因于化学有序度较低的区域中扩散路径的限制。我们还强调了工作温度对扩散的关键作用，应保持远低于退火温度以保持缓慢的扩散效应。我们的研究揭示了 MEA 中化学有序性和缺陷扩散之间的相互作用，并提出了通过改变化学有序性来调整 MEA 扩散率的有效策略。这些见解有助于开发下一代材料，这些材料经过优化，可在高温和辐照条件等具有挑战性的环境中使用。