Reverse hydride transformations in the Pd–H system

Goltsova, M. V.

doi:10.1016/j.ijhydene.2005.04.032

Cited by 12 publications

(8 citation statements)

References 12 publications

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“…Dehydrided specimens display significant hardening in the regions near the exterior free surface edges with the central regions remaining near annealed values. This suggests the b phase nucleates at the surfaces and progresses inward with increasing hydrogenation levels, which fits with the discontinuous fronts of propagation described in the literature [3,22]. The hardened region penetrates in from the exterior free surface to a depth proportional to the amount of b phase hydride formed.…”

Section: Dual Phase Specimenssupporting

confidence: 85%

“…The maximum mole fraction of hydrogen in the a phase at room temperature is 0.008 AE 0.002, and the minimum contained by the b phase is 0.607 AE 0.002 [1]. The a / b phase transformation involves an 11% increase in the lattice parameter, which occurs via a diffusivecooperative shear mechanism [3], increasing the size of the FCC unit cell, with the palladium atoms being systematically displaced and the hydrogen atoms diffusing to the octahedral interstices [4]. This transformation, and its reversal, can induce mechanical effects such as significant plastic strain and increases in dislocation density.…”

Section: Introductionmentioning

confidence: 99%

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Nanoindentation of palladium–hydrogen

Wheeler

Clyne

2012

International Journal of Hydrogen Energy

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Section: Dual Phase Specimenssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Nanoindentation of palladium–hydrogen

Wheeler

Clyne

2012

International Journal of Hydrogen Energy

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“…This plays a critical role in the development of hydride (diffusive-cooperative) transformations in metal-hydrogen systems. 21 We have also shown in our samples that residual stresses induced by the hydrogen release hinder the phase transition. The higher residual stress in sample 1 is possibly related to the larger amount of b-phase initially present in the coating and thus to the larger H content.…”

Section: Resultssupporting

confidence: 66%

In situ XRD characterization of hydrogen desorption from electrochemically deposited Pd coating

et al. 2010

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One of the main problems in electrochemical Pd deposition of coatings is the hydrogen desorption that causes microcracking phenomena. With the aim of understanding the structural changes due to the hydrogen desorption, the kinetics of the phase transformation from hydride to metallic structure has been followed by in situ X-ray diffraction (XRD) experiments. The structural evolution of samples obtained by two different electrochemical baths has been compared. It was found that the solubility and the desorption kinetics of hydrogen are significantly influenced by the presence of structural defects. Residual stresses have been evaluated for both samples by means of 2D X-ray diffraction (XRD 2 ). The presence of amine complexes in the bath seems to contribute to reducing the crystalline dimension of the Pd-phase, and the differences between the specific volumes of a and b phases is reduced for nanostructured coatings.

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“…However, thin palladium membranes easily suffer from hydrogen embrittlement, particularly due to the ␣-␤ phase transition at temperatures below the critical points of the Pd-H system, i.e. 565 K, 1.97 MPa [5,6]. The difference in the specific volumes of the lattices of the ␣-and ␤-phases is up to 10% [7], so that the phase transitions are accompanied by the generation of defects, causing fatal fracture of the thin palladium membranes [8].…”

Section: Introductionmentioning

confidence: 99%