论文标题
第一原理研究FCC铁中溶质引起的低扩散和氦的自我捕获
First-principles study on the solute-induced low diffusion and self-trapping of helium in fcc iron
论文作者
论文摘要
合金元件的添加在金属合金中透射产生的氦（HE）行为中起着至关重要的作用。已经使用基于密度功能理论（DFT）的第一原理计算研究了溶质（Ni，Cr，Ti，P，Si，c）对面部中心立方体（FCC）铁中He对的行为的影响。对于溶质和他的相互作用，我们发现Ti，P，Si和C吸引了他在FCC铁中比Ni和Cr更强大。我们已经确定了He对最稳定的配置，即Hesub-Hetetra对，结合能为1.60 eV。在考虑溶质对He对稳定性的影响时，我们提出了一个独特的结合能量定义。通过应用该定义，我们建议Ti和P可以削弱他的自我捕获，CR和C有益于他自我捕获，而NI与矩阵Fe本身相似。对于HE的扩散（这是形成HE气泡的必要过程），我们确定他在四面体部位中最稳定的间隙，并且可以在纯FCC铁中以0.16 eV迁移。我们进一步发现Ti和Si可以将障碍物增加到0.18和0.20 eV；相反，CR和P分别将屏障降低到0.10和0.06 eV。总结一下计算，我们得出结论，Ti会减少，而CR会增加HE在FCC铁中的扩散和自我捕获。
The addition of alloying elements plays an essential role in helium (He) behaviours produced by transmutation in metal alloys. Effects of solutes (Ni, Cr, Ti, P, Si, C) on the behaviours of He and He-He pair in face-centred cube (fcc) iron have been investigated using first-principles calculations based on density functional theory (DFT). For the interactions of solutes and He, we found that Ti, P, Si, and C attracts He is more potent than Ni and Cr in fcc iron. We have determined the most stable configuration for the He-He pair, which is the Hesub-Hetetra pair with a binding energy of 1.60 eV. In considering the effect of solutes on the stability of the He-He pair, we have proposed a unique definition of binding energy. By applying the definition, we suggest that Ti and P could weaken He self-trapping, and Cr and C are beneficial for He self-trapping, while Ni is similar to the matrix Fe itself. For the diffusion of He, which is the necessary process of forming the He bubble, we determined that the most stable interstitial He is in a tetrahedral site and could migrate with the energy barrier of 0.16 eV in pure fcc iron. We further found that Ti and Si can increase the barrier to 0.18 and 0.20 eV; on the contrary, Cr and P decrease the barrier to 0.10 and 0.06 eV, respectively. Summarizing the calculations, we conclude that Ti decreases while Cr increases the diffusion and self-trapping of He in fcc iron.
