The Peculiarities of Formation of Alloys Structure in the System Ti-Zr-Hf-H

Dolukhanyan, S. K.; Aleksanyan, A. G.; Ter-Galstyan, O. P.; Mayilyan, Davit; Шехтман, В. Ш.; Sakharov, M. K.; Khasanov, Salavat S.

doi:10.1007/978-1-4020-8898-8_92

Cited by 4 publications

(5 citation statements)

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“…These gave 12.6, 9.2, and 8.9 atom%, respectively. 4 The Cmmm structure is only achieved by low-temperature annealing [14]. We saw none of the expected additional Cmmm superlattice peaks in the diffraction patterns of our powders that had rapidly cooled from high temperature.…”

Section: X-ray and Neutron Diffractionmentioning

confidence: 66%

“…Detailed descriptions of the conditions of alloy formation from their corresponding metal hydrides have been presented previously, together with the influence of process parameters, including composition of initial hydrides and phase transformations during dehydrogenation [1]. Upon heating of the compacted mixture of hydrides, e.g., xTiH 2 +( 1-x)ZrH 2 ,a strong activation of the metals occurs at a temperature slightly higher than that of the dissociation of the hydride [1][2][3][4][5]. Using this method, the temperature necessary for the formation of alloys is typically 600-800 8C lower than that by induction (or arc) fusion or by diffusion sintering.…”

Section: Introductionmentioning

confidence: 99%

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Omega-phase in Ti-Hf-Zr alloys produced by the hydride-cycle methodSpecial issue on Neutron Scattering in Canada.

et al. 2010

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Abstract:We report the presence of large proportions of u-phase in Ti-Hf-Zr alloys, prepared using the hydride cycle technique. We show that the u-phase extends across the concentration triangle of Ti-Zr-Hf and report the partitioning of the three metals across the two sites in this structure from neutron and X-ray data. We examine the symmetry of the order parameter governing the b-u phase transition and show that a two-step model for the phase transition involving site ordering followed by displacement is not likely to be correct. We suggest that an interstitial solid solution of oxygen and octahedral vacancies exists, and that the observation of any u-phase diffraction pattern of alloys of these metals at ambient temperature and pressure should be viewed as a potential sign of the presence of oxygen in the octahedral interstitial sites. Résumé : Dans cet article, nous rapportons la présence d'une importante proportion de la phase dite u dans les alliages Ti-Hf-Zr, préparés par une technique de cyclage sous hydrogène (hydride cycle). Nous montrons également que la phase u s'étend à travers le diagramme de concentration triangulaire de Ti-Hf-Zr. De plus, à partir de données de diffractions des neutrons, nous trouvons que les trois métaux se répartissent sur les deux sites distincts dans la structure. Nous examinons la symetrie du paramètre d'ordre qui gouverne la transition de phase b-u et nous montrons qu'un modèle à deux étages pour la transition de phase est improbable. Nous suggérons plutôt la présence d'une solution solide interstitielle d'oxygène et de lacunes octaédriques. De plus, si la phase u est observée dans le diagramme de diffraction d'alliages de ces métaux à température et pression ambiente, on doit la considérer comme un signe possible de la présence d'oxygène sur les sites interstitiels octaédriques.

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Section: X-ray and Neutron Diffractionmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Omega-phase in Ti-Hf-Zr alloys produced by the hydride-cycle methodSpecial issue on Neutron Scattering in Canada.

et al. 2010

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“…The HT method allows the avoidance of the majority of them (in particular, it excludes melting). HT is a high-tech method based on the combination of self-propagating high-temperature synthesis SHS of transition metal hydrides and heat treatment of a mixture of hydrides, resulting in alloy formation [10][11][12]. In the HT method, to obtain high-strength alloys based on transition metals, the powders of hydrides of refractory metals and alloys are used as initial materials.…”

Section: Introductionmentioning

confidence: 99%

“…The advantage of HT is that the alloy is formed at a relatively low temperature (from 900 to 1150 • C) during rapid exposition (from 1 to 2 h). It is important that metals with different values of melting temperature and density should alloy without melting [10][11][12]. Other advantages of the method are relative cheapness, the use of refractory materials, as well as obtaining materials with high purity.…”

Section: Introductionmentioning

confidence: 99%

The Structural and Phase State of the TiAl System Alloyed with Rare-Earth Metals of the Controlled Composition Synthesized by the “Hydride Technology”

Belgibayeva

Abzaev

Karakchieva

et al. 2020

Metals

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The structural state and the quantitative phase analysis of the TiAl system, alloyed with rare-earth metals synthesized using hydride technology, were studied in this work. Using the Rietveld method, the content of the major phases in the initial system Ti(50 at.%)–Al(50 at.%), as well as Ti(49 at.%)–Al(49 at.%), with alloying additions Ta, Y and Dy having a high accuracy was determined. The methods of scanning electron microscopy, transmission electron microscope and X-ray spectral microanalysis of the local areas of the structure for studying the distribution of alloying elements were used. The energies of lattices of separate phases were also determined after the full-profile specification. All the lattices of the identified structures (about 30) turned out to be stable. It was established that in the Ti(49 at.%)–Al(49 at.%) systems under study with alloying additions of metals Ta, Y and Dy, there were intermetallides composed of AlTi3, TiAl in the hexagonal, tetragonal and triclinic units. It is known that after microalloying alloys by Y and Dy metals, the mass fraction of TiAl phases increases significantly (>70%).

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“…The possibility of synthesizing complex intermetallic and quasicrystalline materials based on refractory metals of the zirconium group using hydride technology was shown in [1][2][3][4][5][6][7][8]. These materials are capable of reversibly absorbing hydrogen in significant quantities over 2 wt.% [9][10][11], which allows us to consider them as materials for the storage of hydrogen.…”

Section: Introductionmentioning

confidence: 99%

SYNTHESIS OF HYDROGEN STORAGE MATERIALS IN A Ti-Zr-Ni SYSTEM USING THE HYDRIDE CYCLE TECHNOLOGY DURING DEHYDROGENATION BY AN ELECTRON BEAM IN A VACUUM

Dmytrenko¹,

Dubinko²,

Borysenko³

et al. 2020

Problems of Atomic Science and Technology

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The Peculiarities of Formation of Alloys Structure in the System Ti-Zr-Hf-H

Cited by 4 publications

References 1 publication

Omega-phase in Ti-Hf-Zr alloys produced by the hydride-cycle methodSpecial issue on Neutron Scattering in Canada.

Omega-phase in Ti-Hf-Zr alloys produced by the hydride-cycle methodSpecial issue on Neutron Scattering in Canada.

The Structural and Phase State of the TiAl System Alloyed with Rare-Earth Metals of the Controlled Composition Synthesized by the “Hydride Technology”

SYNTHESIS OF HYDROGEN STORAGE MATERIALS IN A Ti-Zr-Ni SYSTEM USING THE HYDRIDE CYCLE TECHNOLOGY DURING DEHYDROGENATION BY AN ELECTRON BEAM IN A VACUUM

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