Hydrogen absorption into alpha titanium in acidic solutions

Yan, Lei; Ramamurthy, S.; Noël, James J.; Shoesmith, David W.

doi:10.1016/j.electacta.2006.07.017

Cited by 48 publications

(39 citation statements)

References 19 publications

(35 reference statements)

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“…As a result, we obtained the following binding energies of hydrogen: 108 kJ/mol for electrolytic saturation and 102 kJ/mol for gas phase saturation. These data agree with the XRD results for the titanium alloy results [12,19] on determining the binding energy of hydrogen in a titanium alloy after electrolytic satura tion (108 and 106 kJ/mol) and gas phase saturation (100 kJ/mol). This binding energy range for hydrogen in titanium corresponds to hydride, which agrees with our XRD data.…”

Section: Thermally Stimulated Hydrogen Desorptionsupporting

confidence: 81%

Hydrogen accumulation and distribution during the saturation of a VT1-0 titanium alloy by an electrolytic method and from a gas atmosphere

et al. 2014

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Abstract-The accumulation, distribution, and thermally stimulated release of hydrogen in a VT1 0 tita nium alloy during electrolytic saturation and gas phase saturation are studied. After electrolytic saturation, a 0.4 μm thick surface layer consisting of δ hydrides with a binding energy of 108 kJ/mol forms in the alloy. The hydride dissociation after electrolytic saturation in heating occurs in the temperature range 320-370°C. After saturation from a gas atmosphere, δ hydrides with a binding energy of 102 kJ/mol form throughout the alloy volume. The dissociation of the hydrides formed during gas phase saturation in heating occurs in the temperature range 520-530°C. A further increase in the temperature is accompanied by the transformation of titanium from the α into the β modification. At 690-720°C, the phase transformation is completed, and another hydrogen desorption peak appears in a thermally stimulated hydrogen desorption spectrum.

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Section: Thermally Stimulated Hydrogen Desorptionsupporting

confidence: 81%

Hydrogen accumulation and distribution during the saturation of a VT1-0 titanium alloy by an electrolytic method and from a gas atmosphere

et al. 2014

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“…Since the conditions for reduction of D + to D ads exist over this entire potential range, this slowdown in D uptake needs an explanation. The critical solubility of H in Ti for hydride formation at room-temperature ranges from 0.002 to 0.004 in atomic ratio H:Ti for bulk metal, [40][41][42] and from 0.06 to 0.07 for evaporated Ti films. 43,44 The marked difference between bulk and thin-film is undoubtedly due to morphology: bulk metal grains are tightly packed whereas evaporated thin-films contain substantial voids and cracks.…”

Section: Discussionmentioning

confidence: 99%

Hydrogen Absorption into Titanium under Cathodic Polarization: An In-Situ Neutron Reflectometry and EIS Study

Vezvaie¹,

Noël

Tun³

et al. 2013

J. Electrochem. Soc.

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Hydrogen (deuterium) absorption into sputter-coated titanium (Ti) film electrodes during cathodic polarization in heavy water (D 2 O) was monitored using in-situ neutron reflectometry (NR) and electrochemical impedance spectroscopy (EIS). The scattering length density (SLD) of Ti metal increased with increasing cathodic polarization, due to the penetration of deuterium through the surface oxide and into the underlying metal. The rate of D absorption estimated from the NR data showed a pattern with four distinctive regions separated by potential boundaries between −0.35 and −0.4 V SCE and around ∼−0.6 V SCE . EIS results support division of the behavior into these potential ranges. Hydrogen absorption by Ti was observed at potentials <∼−0.35 V SCE , where the capacitance and resistance of the TiO 2 layer dramatically changed. At this point, the D content of the film quickly achieved a level of ∼900 ppm by weight (atom ratio D:Ti ∼ 0.04). Decreased absorption kinetics were observed over the potential region from ∼−0.40 V SCE to −0.6 V SCE , indicating that D absorption was controlled either by a diffusion process through the TiO 2 layer or by the formation of blocking hydrides at the Ti/TiO 2 interface, at the base of the defective locations in the oxide through which the hydrogen was entering. Significant increases in the current density and SLD of the Ti film at potentials more negative than −0.6 V SCE were assigned to widespread hydrogen absorption and TiH x growth within the metal. These observations are consistent with hydrogen ingress through the oxide film, probably via weak points containing electronic defects and disorder, such as grain boundaries and triple points, at potentials as mild as ∼−0.4 V SCE , and with hydrogen penetration through continuous, intact oxide via the previously published redox transformation mechanism, at potentials more negative than −0.6 V SCE . Titanium corrosion processes are often accompanied by hydrogen production. For example, 80% or more of the crevice corrosion process on Ti is driven by the reduction of protons inside the crevice:This leads to the absorption of atomic hydrogen, and can result in extensive hydride formation. 1,2 Cathodic polarization and galvanic coupling with active metals can also cause hydrogen evolution on the Ti surface and hydrogen penetration into the bulk metal. Since hydrogen absorption into Ti structures can lead to their failure by brittle cracking, once the hydrogen concentration achieves a critical level, 3 safe operation of such structures requires a detailed knowledge of the mechanism of hydrogen entry into Ti so that exposure conditions that put the structure at risk of hydrogen-induced cracking can be avoided. A number of studies have been done on the physicochemical properties of Ti/H systems, as well as on hydrogen-induced cracking of Ti.3,4 Here we explore the role of the electrochemical potential in determining whether adsorbed hydrogen atoms generated by water reduction can penetrate the native oxide on Ti.The surface oxide layer play...

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“…The protective surface oxide layer generally present on Ti exposed to air or aqueous systems can hinder hydrogen absorption into the metal [20][21][22][23][24][25][26][27][28][29][30][31][32][33]. This retardation could be due to the lower diffusion coefficient for hydrogen in the oxide.…”

Section: Introductionmentioning

confidence: 99%

“…Hydrogen penetration into the oxide depends on a number of parameters, including the oxide's chemical composition and structure [20,29,34,35], the presence of Ti n+ interstitials and/or oxygen vacancies [36], the types of impurities and their concentration, the adsorption characteristics of the oxide surface [37], the solubility of hydrogen in the oxide, and environmental parameters, such as electrochemical potential [38] and temperature. Given these complexities and the absence of experimental data for aqueous solutions, it is difficult to predict how fast hydrogen will be transported through the oxide and what fraction of the hydrogen atoms generated on the oxide surface will reach the Ti substrate.…”

Section: Introductionmentioning

confidence: 99%