Evaluation of hydrogen sorption and desorption for Ti-6A1-4V alloy as a vacuum vessel material

Hirohata, Yuko; Aihara, Yasuki; Hino, Tomoaki; Miki, N.; Nakagawa, Satoshi

doi:10.1016/b978-0-444-82762-3.50061-6

Cited by 3 publications

(2 citation statements)

References 12 publications

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“…The diffusion coefficient of hydrogen in different titanium phases as the function of temperature was reported in [ 47 , 48 ]:

where D is the diffusion coefficient (m 2 /s), R is the gas constant (cal mol −1 K −1 ), T is the temperature (K). It has been noted that the diffusion of hydrogen in Ti-6Al-4V significantly depends on microstructure and β phase content and could vary from 10 −13 to 10 −10 m 2 /s at 20 °C [ 49 ]. According to these equations, the calculated values of H hydrogen diffusion in titanium at 500 °C (773 K) are D α = 2.1 × 10 −10 m 2 /s and D β = 2.6 × 10 −9 m 2 /s.…”

Section: Discussionmentioning

confidence: 99%

Influence of Manufacturing Parameters on Microstructure and Hydrogen Sorption Behavior of Electron Beam Melted Titanium Ti-6Al-4V Alloy

et al. 2018

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Influence of manufacturing parameters (beam current from 13 to 17 mA, speed function 98 and 85) on microstructure and hydrogen sorption behavior of electron beam melted (EBM) Ti-6Al-4V parts was investigated. Optical and scanning electron microscopies as well as X-ray diffraction were used to investigate the microstructure and phase composition of EBM Ti-6Al-4V parts. The average α lath width decreases with the increase of the speed function at the fixed beam current (17 mA). Finer microstructure was formed at the beam current 17 mA and speed function 98. The hydrogenation of EBM Ti-6Al-4V parts was performed at the temperatures 500 and 650 °С at the constant pressure of 1 atm up to 0.3 wt %. The correlation between the microstructure and hydrogen sorption kinetics by EBM Ti-6Al-4V parts was demonstrated. Lower average hydrogen sorption rate at 500 °C was in the sample with coarser microstructure manufactured at the beam current 17 mA and speed function 85. The difference of hydrogen sorption kinetics between the manufactured samples at 650 °C was insignificant. The shape of the kinetics curves of hydrogen sorption indicates the phase transition αH + βH→βH.

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“…The diffusion coefficient of hydrogen in different titanium phases as the function of temperature was reported in [ 47 , 48 ]:

Section: Discussionmentioning

confidence: 99%

Influence of Manufacturing Parameters on Microstructure and Hydrogen Sorption Behavior of Electron Beam Melted Titanium Ti-6Al-4V Alloy

et al. 2018

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“…Hydrogen diffusion in titanium Ti-6Al-4V alloy is determined by many factors, such as hydrogenation temperature, hydrogen pressure, microstructure, phase composition, defect structure, and other [46]. At the indicated hydrogenation conditions, the diffusion coefficients in the α and β phases, evaluated from equations [47]:…”

Section: Sem and Tem Analysismentioning

confidence: 99%

Hydrogen-Induced Phase Transformation and Microstructure Evolution for Ti-6Al-4V Parts Produced by Electron Beam Melting

Pushilina

Панин

Сыртанов

et al. 2018

Metals

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In this paper, phase transitions and microstructure evolution in titanium Ti-6Al-4V alloy parts produced by electron beam melting (EBM) under hydrogenation was investigated. Hydrogenation was carried out at the temperature of 650 • C to the absolute hydrogen concentrations in the samples of 0.29, 0.58, and 0.90 wt. %. Comparative analysis of microstructure changes in Ti-6Al-4V alloy parts was performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Furthermore, in-situ XRD was used to investigate the phase transitions in the samples during hydrogenation. The structure of Ti-6Al-4V parts produced by EBM is represented by the α phase plates with the transverse length of 0.2 µm, the β phase both in the form of plates and globular grains, and metastable α" and ω phases. Hydrogenation to the concentration of 0.29 wt. % leads to the formation of intermetallic Ti 3 Al phase. The dimensions of intermetallic Ti 3 Al plates and their volume fraction increase significantly with hydrogen concentration up to 0.58 wt. % along with precipitation of nano-sized crystals of titanium δ hydrides. Individual Ti 3 Al plates decay into nanocrystals with increasing hydrogen concentration up to 0.9 wt. % accompanied by the increase of proportion and size of hydride plates. Hardness of EBM Ti-6Al-4V alloy decreases with hydrogen content.

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Japanese universities' activities for PFC development and PMI studies

Hino

1998

Fusion Engineering and Design

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Evaluation of hydrogen sorption and desorption for Ti-6A1-4V alloy as a vacuum vessel material

Cited by 3 publications

References 12 publications

Influence of Manufacturing Parameters on Microstructure and Hydrogen Sorption Behavior of Electron Beam Melted Titanium Ti-6Al-4V Alloy

Influence of Manufacturing Parameters on Microstructure and Hydrogen Sorption Behavior of Electron Beam Melted Titanium Ti-6Al-4V Alloy

Hydrogen-Induced Phase Transformation and Microstructure Evolution for Ti-6Al-4V Parts Produced by Electron Beam Melting

Japanese universities' activities for PFC development and PMI studies

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