Solution and diffusion of hydrogen isotopes in tungsten-rhenium alloy

• Published in: Journal of nuclear materials Vol. 491; pp. 206 - 212
• Main Authors: Ren, Fei, Yin, Wen, Yu, Quanzhi, Jia, Xuejun, Zhao, Zongfang, Wang, Baotian
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-08-2017; Elsevier BV
• Subjects: Alloys; Crystals; Diffusion; Diffusion coefficient; Energy; Energy of solution; First-principle calculations; Ground state; Hydrogen; Hydrogen isotopes; Hydrogen storage; Hydrogen-based energy; Irradiation; Isotopes; Lattice vibration; Migration; Neutron irradiation; Rhenium; Solubility; Solution and diffusion; Studies; Transmutation; Tungsten; Tungsten base alloys; Tungsten isotopes; Tungsten-rhenium alloy; Vibration; Vibration mode; Zero point energy; Tungsten-rhenium alloy; Solution and diffusion; Hydrogen isotopes; First-principle calculations
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2017.04.057

Rhenium is one of the main transmutation elements forming in tungsten under neutron irradiation. Therefore, it is essential to understand the influence of rhenium impurity on hydrogen isotopes retention in tungsten. First-principle calculations were used to study the properties of hydrogen solution and diffusion in perfect tungsten-rhenium lattice. The interstitial hydrogen still prefers the tetrahedral site in presence of rhenium, and rhenium atom cannot act directly as a trapping site of hydrogen. The presence of rhenium in tungsten raises the solution energy and the real normal modes of vibration on the ground state and the transition state, compared to hydrogen in pure tungsten. Without zero point energy corrections, the presence of rhenium decreases slightly the migration barrier. It is found that although the solution energy would tend to increase slightly with the rising of the concentration of rhenium, but which does not influence noticeably the solution energy of hydrogen in tungsten-rhenium alloy. The solubility and diffusion coefficient of hydrogen in perfect tungsten and tungsten-rhenium alloy have been estimated, according to Sievert's law and harmonic transition state theory. The results show the solubility of hydrogen in tungsten agrees well the experimental data, and the presence of Re would decrease the solubility and increase the diffusivity for the perfect crystals.
•With or without ZPE corrections, the properties of H solution and diffusion in W and W-Re alloy are investigated.•The presence of Re in W increases the solution energy and the real normal modes of vibration, compared to H in pure W.•The concentration of Re does not influence noticeably the properties of H solution and diffusion in W-Re alloy.•For H in perfect W and W-Re crystals, the presence of Re would decrease the solubility and increase the diffusivity.