Experimental and theoretical studies have shown that helium (He) atoms in metal tend to form into nano-sized bubbles which greatly affects mechanical properties of metals. Thus, designing nanostructure to control the growth of He bubbles and increase its radiation resistance is an important task. In this work, we systematically study the atomistic mechanism on how the carbon (C) nanomaterials embedded inside metals with different crystal structures (FCC-Ni and BCC-Fe) disperse or release He atoms using molecular dynamics simulations. The dynamic evolution of He atoms in different Ni/C and Fe/C nanocomposites were observed and compared. It is found that the presence of multiple C₇₂ with vacancy defects and graphene with multiple vacancy defects can suppress the formation of large He bubbles and dislocations by helping to disperse He atoms, while, the C nanotube with vacancy defects can suppress the formation of large He bubbles and dislocations by helping to release He atoms. The formation energies of He in different Ni/C and Fe/C nanocomposites were also calculated to explain why the He atoms tend to diffuse into the region near C structures. The average diffusion coefficients of He in bulk Ni and bulk Fe were calculated to explain the mechanism for the better abilities of C structures in Fe/C nanocomposites than in Ni/C nanocomposites help to disperse or release He atoms.

实验和理论研究表明，金属中的氦（He）原子容易形成纳米级气泡，极大地影响金属的力学性能。因此，设计纳米结构以控制 He 气泡的生长并增加其抗辐射性是一项重要任务。在这项工作中，我们使用分子动力学模拟系统地研究了嵌入具有不同晶体结构的金属（FCC-Ni 和 BCC-Fe）中的碳 (C) 纳米材料如何分散或释放 He 原子的原子机制。观察和比较了不同 Ni/C 和 Fe/C 纳米复合材料中 He 原子的动态演化。发现存在多个 C ₇₂具有空位缺陷的石墨烯和具有多个空位缺陷的石墨烯可以通过帮助分散He原子来抑制大He气泡和位错的形成，而具有空位缺陷的C纳米管可以通过帮助释放He原子来抑制大He气泡和位错的形成. 还计算了 He 在不同 Ni/C 和 Fe/C 纳米复合材料中的形成能，以解释为什么 He 原子倾向于扩散到 C 结构附近的区域。计算了 He 在块状 Ni 和块状 Fe 中的平均扩散系数，以解释 Fe/C 纳米复合材料中 C 结构比 Ni/C 纳米复合材料中更好的有助于分散或释放 He 原子的机制。