In previous experiments, compounds TiC, TaC, and ZrC are often added in W to improve the mechanical and thermal properties. However, it is still not clear how atomic Ti, Ta and Zr coexisted with C will affect H behaviors in W. In this work, systematical \emph{ab initio} calculations are carried out to study the interactions among alloying atoms (Ti, Ta and Zr), H, and C. The results illustrate that substitutional alloying atoms Ti, Ta, and Zr can trap H atom, and increase the retention of H in W. The effect of Ti on raising H retention is the strongest, followed by that of Zr and Ta. All Ti-C, Ta-C, and Zr-C can exist in W, and Zr-C is the most stable while the stability of Ta-C is relatively low. The stability of Ti-C is between Zr-C and Ta-C. The binding strength of Zr-C-H is the largest, followed by that of Ti-C-H and Ta-C-H in W, suggesting H retention in W-Zr-C may be the largest while H retention in W-Ta-C may be relatively low. The movement of H is much easier than that of C in W. The presence of alloying atoms Ti, Ta, and Zr in W affects the movement of H and C: the diffusion of H away from the alloying atoms is more difficult than that moving close to the alloying atoms, while the movement of C atoms approaching the alloying atoms is relatively difficult.

中文翻译：

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W-Ti-C、W-Ta-C 和 W-Zr-C 合金中氢的保留：从头开始研究

在以前的实验中，通常在 W 中添加化合物 TiC、TaC 和 ZrC，以提高机械和热性能。然而，目前尚不清楚原子 Ti、Ta 和 Zr 与 C 共存将如何影响 W 中的 H 行为。在这项工作中，系统进行了\emph {ab initio} 计算来研究合金原子（Ti、Ta和Zr)、H和C。结果表明置换合金原子Ti、Ta和Zr可以俘获H原子，增加H在W中的保留。Ti对提高H保留的作用最强，其次是Zr 和 Ta。所有Ti-C、Ta-C和Zr-C都可以存在于W中，Zr-C最稳定，而Ta-C的稳定性相对较低。Ti-C的稳定性介于Zr-C和Ta-C之间。W中Zr-CH的结合强度最大，其次是Ti-CH和Ta-CH，表明 W-Zr-C 中的 H 保留可能是最大的，而 W-Ta-C 中的 H 保留可能相对较低。H 在 W 中的运动比 C 容易得多。 W 中合金原子 Ti、Ta 和 Zr 的存在影响了 H 和 C 的运动：H 从合金原子中扩散出去比运动更困难靠近合金原子，而 C 原子靠近合金原子的运动相对困难。