Hydrogen Permeation Characteristics and Structural Features of Melt-Spun Ni-Nb-Zr Amorphous Alloy Membranes

摘要

We examined the hydrogen permeation of melt-spun Ni-Nb-Zr amorphous alloys. The interatomicspacing in the (Ni0.6Nb0.4)100-xZrx (x = 0 – 50) amorphous structure increased with increasing Zr content.The permeability of the alloys is strongly dependent on alloy compositions. The maximum hydrogenpermeability was 1.59 × 10 -8 (mol/m sPa 1/2 ) at 673 K for the (Ni0.6Nb0.4)50Zr50 amorphous alloy. It isnoticed that the permeability is as high as that of pure Pd metal at 673 K. And the hydrogen permeabilityof the amorphous alloy is larger than that of pure Pd metal at the temperature below 673 K. Moreover, itis important to study the relationship between hydrogen permeation and atomic structure of amorphousalloys to understand the hydrogen permeation mechanism through amorphous alloys. We investigatedthe amorphous structures of these alloys by the radial distribution function (RDF) analysis. As a result, itwas found that the number of the Zr-Zr pair which has larger interatomic distance than any other pairssuch as Ni-Ni, Nb-Nb, Ni-Nb, Ni-Zr and Nb-Zr increased with increasing Zr content. Therefore,hydrogen atoms can permeate more easily through the Ni-Nb-Zr amorphous membrane with higher Zrcontent in the composition range of Ni-Nb-Zr amorphous alloys prepared in this work. Thesepermeation characteristics and structural features indicate the possibility of future practical use of themelt-spun amorphous alloys as a hydrogen permeable membrane.