Effect of electrochemical modification of titanium hydride fraction on oxygen content in surface and deep layers

Abstract The paper presents a study of the microstructure and oxygen concentration in the surface and deep layers of fractions of unmodified titanium hydride and titanium hydride modified by electrodeposited layers of Ti and Cu at temperatures of 300-900 ° C. The composition of the oxide layer and the concentration of titanium and oxygen atoms are estimated. It is shown that an increase in the thickness and compaction of the oxide layer with increasing temperature prevents the penetration of oxygen into the deep layers of the unmodified fraction of titanium hydride. Modification of titanium hydride by electrochemical deposition of metallic titanium at a temperature of 700 °C reduces the oxygen concentration in titanium hydride at a layer depth of 50 μm from 35 wt% to 12.5 wt%. Electrodeposition of coatings based on titanium and copper at 700 °C reduces the oxygen concentration to 9.2 wt%, which may be due to the protective mechanism of the formed copper titanate layer. At 900 °C, in the modification layer based on titanium and copper, due to the eutectoid transformation of the β-phase of titanium, the process of contact melting occurs and a multiphase zone is formed. The oxygen concentration at a layer depth of 50 μm is no more than 12.4 wt%.

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Microstructure and Nanoindentation Studies of Hydridated Zircaloy-4 Claddings After High Temperature Oxidation

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4049053 ◽

2020 ◽

Vol 7 (2) ◽

Author(s):

Petra Gávelová ◽

Patricie Halodová ◽

Daniela Marušáková ◽

Ondřej Libera ◽

Jakub Krejčí ◽

...

Keyword(s):

High Temperature ◽

Oxygen Concentration ◽

Hydrogen Content ◽

Oxygen Solubility ◽

Pressurized Water ◽

Temperature Oxidation ◽

Β Phase ◽

Significant Difference ◽

Water Reactors ◽

Increasing Temperature

Abstract Zirconium-based alloys are one of the most significant materials in thermal-neutron reactor systems. With very low neutron capture cross section, good corrosion resistance, mechanical strength and resistance to neutron radiation damage, zirconium alloys are used for fuel claddings. Cladding materials are still improved and tested in normal as well as critical reactor conditions. Zircaloy-4 (Zr-1.5Sn-0.2Fe-0.1Cr) is used for west types of light-water reactors, Pressurized Water Reactors (PWR). In our study, Zircaloy-4 cladding tubes were high-temperature oxidized in steam at the series of temperatures from 950 up to 1425 °C to simulate PWR reaching severe accident conditions. To observe the influence of hydrogen (H) diffusing from the coolant water on oxidation process, the specimens with ∼1000 ppm H were compared to the specimens with almost no hydrogen content. Wave Dispersive Spectroscopy (WDS) and nanoindentation were performed in line profiles across the cladding wall. Both methods contributed to verify the pseudobinary Zircaloy-4/oxygen phase diagram with focus on determination of phase boundaries. The increase of oxygen concentration with increasing temperature was observed. Moreover, oxygen concentration profiles and related change in nanohardness and Young's modulus showed the effect of hydrogen on the cladding microstructure. Hydrogen dissolved in metallic matrix increases the oxygen solubility in prior β-phase, the specimens with 1000 ppm H showed the higher oxygen content at almost all temperatures. As well, material hardening was observed on specimens with 1000 ppm H with significant difference in β-phase, measured on specimens exposed to lowest and highest oxidation temperature. Thus, with increasing temperature and hydrogen content, increased oxygen solubility affects the cladding ductility.

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Experimental Studies on Pb-Bi Flow Technology and Steel Compatibility With Pb-Bi

12th International Conference on Nuclear Engineering, Volume 1 ◽

10.1115/icone12-49285 ◽

2004 ◽

Cited By ~ 1

Author(s):

Masatoshi Kondo ◽

Minoru Takahashi ◽

Susumu Yoshida ◽

Naoki Sawada ◽

Akira Yamada ◽

...

Keyword(s):

Mechanical Strength ◽

Oxide Layer ◽

Oxygen Concentration ◽

Corrosion Test ◽

Oxygen Sensor ◽

Performance Test ◽

Pipe Wall ◽

Steel Corrosion ◽

Strength Test ◽

Steel Matrix

For the development of the Pb-Bi cooled FBR and the ADS with Pb-Bi target, the compatibility of steels for core, structural and window materials with high temperature Pb-Bi is one of the critical issues. The effect of corrosion on the mechanical strength of steels should be also concerned. An oxide layer which is formed and self-healed on the steel surface in Pb-Bi is expected to improve the compatibility if oxide potential in Pb-Bi is controlled and monitored adequately to form stable oxide layer. Therefore, monitoring technology of oxygen concentration in Pb-Bi is required. In the present study, a performance test of oxygen sensor, a steel corrosion test and a steel mechanical strength test, or a pipe rupture test, were performed as follows: (1) Test of oxygen sensor: For the monitor of the oxygen potential in Pb-Bi, a thermal stress proof type oxygen sensor made of electrolyte conductor (MgO-ZrO2 and Y2O3-ZrO2) with the reference fluid of oxygen saturated bismuth was developed, and the performance test was conducted using the corrosion test loop. The performance was stable and reliable in the 1000-hour operation. The electromotive forces (EMF) of the sensor cells of MgO-ZrO2 and Y2O3-ZrO2 were nearly the same as each other, and they were not destructed during the 1000-operation. (2) Steel corrosion test: High Cr steels including heat resisting steels were exposed to a liquid Pb-Bi flow at the temperature of 550°C, the velocity of 1m/s, the oxygen concentration of 1.7×10−8wt% and the temperature difference of 150°C for 1000 and 500 hours. It was found that weight losses were lower in general in the steels with higher Cr content. The steels with high Cr, Si and Al formed thin oxide layers and exhibited better compatibility with Pb-Bi. (3) Steel mechanical strength test (pipe rupture test): Metallurgical analysis for ruptured pipe made of SS-316 was performed. The pipe had experienced the exposure to Pb-Bi at 400°C for 3440 hours, at 350°C for 4 hours, at 300°C for 50 hours, and at 250°C for 622 hours. Pipe rupture occurred possibly due to thermal expansion of Pb-Bi at heat-up processes. The results of the analysis indicated that Pb-Bi penetration to steel matrix occurred more seriously near the ruptured part than the other part of the pipe. The analytical result suggested that a brittle fracture might occur in the inner part of the ruptured pipe wall by liquid metal embrittlement because of Pb-Bi penetration, whereas dimples observed suggested that ductile fracture might occur in the outer part of the ruptured pipe wall.

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Pzt Interaction with Metal and Oxides Studied by Rutherford Backscattering Spectrometry

MRS Proceedings ◽

10.1557/proc-243-101 ◽

1991 ◽

Vol 243 ◽

Cited By ~ 12

Author(s):

Peter Revesz ◽

Jian Li ◽

Nicholas Szabo ◽

James W. Mayer ◽

David Caudillo ◽

...

Keyword(s):

Oxygen Concentration ◽

Internal Oxidation ◽

Rutherford Backscattering Spectrometry ◽

Metal Electrode ◽

Rutherford Backscattering ◽

Annealing Behavior ◽

Temperature Range ◽

Pzt Film ◽

Increasing Temperature

AbstractAnnealing behavior in oxygen ambients of the of the ferroelectric PZT on Hf and Zr electrodes has been studied in the temperature range of 500-800°C using the 3.045MeV O16(∝,∝)O16 resonance in backscattering spectrometry. Internal oxidation of the buried metal electrode was observed. Oxygen concentration of the PZT film decreases with increasing temperature. Pb loss of the PZT film occurred above 700°C.

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Surface modification of titanium hydride with epoxy resin via microwave-assisted ball milling

Applied Surface Science ◽

10.1016/j.apsusc.2014.08.090 ◽

2014 ◽

Vol 316 ◽

pp. 632-636 ◽

Cited By ~ 10

Author(s):

Rong Ning ◽

Ding Chen ◽

Qianxia Zhang ◽

Zhibing Bian ◽

Haixiong Dai ◽

...

Keyword(s):

Surface Modification ◽

Epoxy Resin ◽

Ball Milling ◽

Titanium Hydride ◽

Microwave Assisted ◽

Modification Of Titanium

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Formation of nanoporous oxide layer over a binary β-phase titanium in simulated body fluid

Journal of Porous Materials ◽

10.1007/s10934-011-9507-4 ◽

2011 ◽

Vol 19 (5) ◽

pp. 573-577 ◽

Cited By ~ 11

Author(s):

M. Karthega ◽

N. Rajendran

Keyword(s):

Simulated Body Fluid ◽

Oxide Layer ◽

Body Fluid ◽

Β Phase

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Structural and Electrical Changes in BIMNVOX Oxide-Ion Conductor

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.316-317.7 ◽

2011 ◽

Vol 316-317 ◽

pp. 7-22 ◽

Cited By ~ 7

Author(s):

Saba Beg ◽

Shehla Hafeez ◽

Niyazi A.S. Al-Areqi

Keyword(s):

Solid Solutions ◽

X Ray Diffraction ◽

Structural Investigations ◽

Ion Conductor ◽

Polymorphic Transitions ◽

Oxide Ion Conductor ◽

Β Phase ◽

Ft Ir ◽

Increasing Temperature ◽

Oxide Ion

Ceramic solid solutions Bi4MnxV2–xO11–(x/2)–δ in the composition range 0.07 ≤ x ≤ 0.30 were obtained by solid state synthesis. Structural investigations were carried out by using a combination of FT-IR and powder X-ray diffraction technique. Polymorphic transitions (β↔γ and γ′↔γ) were detected by DTA and variation in the Arrhenius plots of conductivity. The solid solutions with composition 0.07 ≤ x ≤ 0.17 are isostructural with the orthorhombic β-phase, and those with x ≤ 0.30 represent tetragonal γ-phase. With increasing Mn concentration, the conductivity of solid solutions increases from 3.684×10-6 (x = 0.07) to 2.467×10-5 (x = 0.17). AC impedance plots show that the conductivity is mainly due to the grain contribution which is evident in the enhanced short range diffusion of oxide ion vacancy in the grains with increasing temperature.

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