TY - JOUR

T1 - Structure and hydrogen permeability of V–15Ni alloy

AU - Baraban, A.

AU - Gabis, I.

AU - Kozhakhmetov, S.

AU - Murzinova, M.

AU - Piven, V.

AU - Sidorov, N.

AU - Sipatov, I.

AU - Voyt, A.

PY - 2019/10/18

Y1 - 2019/10/18

N2 - The structure of the V–15Ni at.% alloy before and after hydrogen permeability tests was investigated by means of XRD and SEM with EDS analysis. We have found that decomposition of supersaturated V-based solid solution with variable Ni content occurred during testing. The volume fraction of the solid solution decreased and the fraction of V3Ni phase increased during permeability testing, thus bringing the alloy to nearly equilibrium. The membrane without Pd coating showed satisfactory hydrogen fluxes with a significant impact of the surface dissociation rate of hydrogen. The shape of hydrogen permeation curves at the downstream side of the membrane at various temperatures was unusual. We attribute it to the high concentration of dissolved hydrogen in the metal lattice and its effect on the hydrogen diffusivity and solubility. In addition, the multiphase structure with non-uniform distribution of nickel both between the phases and within the BCC solid solution (and, consequently, different hydrogen concentrations) may cause dilatation or compressing effect on neighbouring micro-volumes of the alloy.

AB - The structure of the V–15Ni at.% alloy before and after hydrogen permeability tests was investigated by means of XRD and SEM with EDS analysis. We have found that decomposition of supersaturated V-based solid solution with variable Ni content occurred during testing. The volume fraction of the solid solution decreased and the fraction of V3Ni phase increased during permeability testing, thus bringing the alloy to nearly equilibrium. The membrane without Pd coating showed satisfactory hydrogen fluxes with a significant impact of the surface dissociation rate of hydrogen. The shape of hydrogen permeation curves at the downstream side of the membrane at various temperatures was unusual. We attribute it to the high concentration of dissolved hydrogen in the metal lattice and its effect on the hydrogen diffusivity and solubility. In addition, the multiphase structure with non-uniform distribution of nickel both between the phases and within the BCC solid solution (and, consequently, different hydrogen concentrations) may cause dilatation or compressing effect on neighbouring micro-volumes of the alloy.

KW - Hydrogen permeability

KW - Microstructure

KW - Supersaturated BCC solid solution

KW - V-Ni alloys

KW - PERMEATION CHARACTERISTICS

KW - PURIFICATION

KW - MEMBRANES

KW - DIFFUSION

UR - http://www.scopus.com/inward/record.url?scp=85072323525&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/structure-hydrogen-permeability-v15ni-alloy

U2 - 10.1016/j.ijhydene.2019.08.224

DO - 10.1016/j.ijhydene.2019.08.224

M3 - Article

AN - SCOPUS:85072323525

VL - 44

SP - 27492

EP - 27498

JO - International Journal of Hydrogen Energy

JF - International Journal of Hydrogen Energy

SN - 0360-3199

IS - 50

ER -