Hydrogen Diffusivity and Solubility in Internally Oxidized Pd0.97Zr0.03 and Pd0.97Nb0.03 Alloys

E.R. Lagreca; Viviane M. Azambuja; Dílson Silva dos Santos

doi:10.4028/www.scientific.net/DDF.297-301.715

Paper Titles

Silicon Dioxide as a Boundary for Oxygen Outdiffusion from CZ-Si
p.688

Cu Ti Formation in Nb Ti/Cu Superconducting Strand Monitored by In Situ Techniques
p.695

Structural Relaxation Process by Addition of B in CuHfTi Amorphous Alloys
p.702

Heat Transfer in Black Holes
p.708

Hydrogen Diffusivity and Solubility in Internally Oxidized Pd_0.97Zr_0.03 and Pd_0.97Nb_0.03 Alloys
p.715

Hydrogen Diffusivity and Hydride Formation in Rich-Zirconium Alloys Used in Nuclear Reactors
p.722

Three-Dimensional Study of Heat and Mass Transfer in a Partially Porous Elongated Cavity
p.728

Effects of the Microstructure on the Hydrogen Diffusivity in Ni-Based Superalloy 718
p.733

Modeling of Turbulent Flow and Heat Transfer in Graphitic Foams
p.739

HomeDefect and Diffusion ForumDefect and Diffusion Forum Vols. 297-301Hydrogen Diffusivity and Solubility in Internally...

Hydrogen Diffusivity and Solubility in Internally Oxidized Pd_0.97Zr_0.03 and Pd_0.97Nb_0.03 Alloys

Abstract:

Internally oxidized (I.O.) Pd0.97Zr0.03 and Pd0.97Nb0.03 alloys were submitted to gas permeation tests with temperatures in the range of 473-873 K. The internal oxidation was kept in a conventional furnace at 1073 K for 24 hours in air contact. The formation of nano-oxides, ZrO2 and Nb2O5, dispersed in the Pd matrix was observed. SEM images showed a preferential segregation of these oxides in the grain boundaries. It was observed that the diffusion coefficient in the sample containing Nb oxide was smaller than that in the Pd-Zr oxide. The effect of hydrogen pressure was investigated in the Pd-Nb samples. It was observed that the hydrogen diffusion coefficient increases with increasing the pressure. The hydrogen solubility is bigger for the Pd-Zr internally oxidized. This effect is attributed to the Zr nanoxides, which are smaller than Pd-Nb precipitates and then offer more interface for trapping the hydrogen.