Hydrogen diffusion and trapping in nanocrystalline tungsten

Entropy based fingerprint for local crystalline order

“…The configuration of the nanocrystalline Al was constructed using Voronoi tesselation 5,34 . The mean grain size was 5 nm and the system contained 255064 atoms.…”

Object kinetic Monte Carlo simulations of irradiated tungsten for nuclear fusion reactors

“…On the contrary, in NW simulations, H retention at ~400 nm is not observed. [165] observed H retention at GBs in W at temperatures ranging from 600 to 1200 K whilst Piaggi et al [164] obtained similar results between 1200 and 2000 K. However, at such high temperatures, more physical processes might take place apart from those described at 300 K in the present…”

“…The fact that the formation energy of vacancies in the GB region [161,162] is lower than that in the bulk [66] may facilitate the trapping of H atoms in vacancies formed at the GBs. Thus, the role of vacancies (and in turn, temperature) in the case of the observed H concentration enhancement at the GB region is not clear [164,165].…”

“…Thus, GBs might act as preferential diffusion path for H atoms [163]. On the other hand, some other works report that the migration energy along the GBs is higher than in the bulk [164]. Therefore, the physical mechanisms for neither FPs nor H atoms at GBs are well understood.…”

Hydrogen Permeation, and Mechanical and Tribological Behavior, of CrNx Coatings Deposited at Various Bias Voltages on IN718 by Direct Current Reactive Sputtering

“…Despite its advantages, this alloy is susceptible to hydrogen embrittlement caused by the penetration of hydrogen resulting in degradation and catastrophic failure [2,3]. It is well-known that grain boundaries play an essential role in hydrogen-induced cracking and embrittlement in polycrystalline metallic materials [4][5][6][7][8][9][10][11]. It has been reported that at a high hydrogen concentration, the δ-phase in IN718 dramatically reduces the ductility of the alloy [12].…”