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Indexed by:期刊论文

Date of Publication:2017-02-01

Journal:JOURNAL OF NUCLEAR MATERIALS

Included Journals:SCIE、EI

Volume:484

Page Number:276-282

ISSN No.:0022-3115

Key Words:H retention; Diffusion; Vanadium alloys; First principles

Abstract:We systemically investigated diffusion and retention of hydrogen (H) in vanadium (V) in presence of Ti/ Cr and determined the stability of H-n clusters and H-n-vacancy clusters (n = 1-6) near Cr/Ti using first principles calculations. H prefers a tetrahedral site near Ti than other interstitial sites. H-Cr interactions have a weak repulsion contrarily H-Ti interactions have a weak attraction. Kinetically, H diffusion barrier decreases towards Ti, while it increases towards Cr. Ti and Cr block H mobility in V alloys. Moreover, HnTi clusters are quite stable while HnCr clusters are less stable. Ti enhances H retention by acting as a trapping site for multiple H atoms in similar with vacancy, and a Ti atom can trap at least six H atoms. The stability of H-vacancy-Cr/Ti complexes and vacancy-Cr/Ti trapping for multiple H atoms are discussed. The findings are valuable for understanding the mechanism of H bubble nucleation and H embrittlement under irradiation. (C) 2016 Elsevier B.V. All rights reserved.