The Influence of Complex Doping on Kinetics of Decomposition and Thermal Stability of Mg-Based Mechanical Alloys

Mechanical alloys (MАs) were synthesized by the method of reactive mechanical alloying. At a hydrogen pressure of 0.1 MPa, with the use of thermal desorption spectroscopy, the thermal stability, the kinetics of hydrogen desorption from the hydride phase MgH2 of the obtained MAs were studied. It has been established that the complex doping by of Fe, Si, Ti, leads to a significant improvement in the of hydrogen desorption from the hydride phase MgH2 of MA synthesized by the RMA. Hydrogen capacity CH of MА after reactive grinding for 20 h. was found to be equal to 5.7 % wt. Due to this alloying, the decrease in the thermodynamic stability of MgH2 is not established. The tested materials showed a high potential as hydrogen storage alloys especially for stationary application.

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Mechanical alloys Mg-Me (Me: Ti, Fe, Ni, Al) & Mg-Me1-Me2(Ме1:Al, Me2: Ti, Fe, Ni) with low resistance and improved kinetics of hydrogenation/dehydrogenation for hydrogen storage applications

French-Ukrainian Journal of Chemistry ◽

10.17721/fujcv6i1p31-55 ◽

2018 ◽

Vol 6 (1) ◽

pp. 31-55 ◽

Cited By ~ 1

Author(s):

O. Ershova ◽

V. Dobrovolsky ◽

Y. Solonin

Keyword(s):

Thermal Stability ◽

Hydrogen Storage ◽

Sorption Capacity ◽

Hydrogen Pressure ◽

Hydrogen Desorption ◽

Decomposition Kinetics ◽

Hydrogen Storage Alloys ◽

Mechanically Alloyed ◽

Kinetics Of ◽

Complex Doping

Changes in MgH2 decomposition kinetics were investigated in dependence on complex doping of MgH2 by Al, Ti, Ni, and Fe. Reactive mechanochemical alloying method (RMA) was applied in the temperature descending regime. It was found that addition of Al+Ni+Ti, Al+Ti, Fe+Ti (see below) and Al+Fe elements combinations led to a lower thermal stability and, consequently, to a lowering of the temperature of hydrogen desorption onset. Whereas desorption began at temperature of 320 °C from the pure MgH2, the aditions of Al, Ni, Ti and Fe lowered the start of the desorption down to 250°C (at hydrogen pressure 0.1 MPa in the reactor). Very fast desorption kineticsprecize at 300 0C and PH 2= 0.1 MPa were observed for Mg+Me mixture in comparison with the pure Mg. Sorption capacity of investigated mechanically-alloyed composites varied from 5 to 6.5 wt. % H2. The tested materials showed a high potential as hydrogen storage alloys especially for stationary application.

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Hydrogen Sorption Properties, Thermal Stability and Kinetics of Hydrogen Desorption From the Hydride Phase of The MgH2 of a Mechanical Alloys of Magnesium with Ti, Ni and Y

Фізика і хімія твердого тіла ◽

10.15330/pcss.21.1.167-175 ◽

2020 ◽

Vol 21 (1) ◽

pp. 167-175

Author(s):

O. G. Ershova ◽

V. D. Dobrovolsky ◽

Yu. M. Solonin

Keyword(s):

Thermal Stability ◽

Thermodynamic Stability ◽

Hydrogen Desorption ◽

Sorption Properties ◽

Hydrogen Sorption ◽

Hydride Phase ◽

Phase Content ◽

Stability Kinetics ◽

Kinetics Of

The mechanical alloys-composite MАs (Mg +10 % wt.Ti + 5 % wt.Y and Mg +10 % wt.Ni + 5 % wt.Y) were synthesized. The phase content, microstructure, the thermal stability, kinetics of hydrogen desorption from the MgH2 hydride phase of the obtained MAs were studiedby using XRD, SEM, TDS methods. It has been established that the addition of Ti + Y and Ni + Y to magnesium leads to significant improvement in the kinetics of hydrogen desorption from the MgH2 hydride phase, which is evidenced by a significant reduction (in 6 and 15 times)in the time of release of all hydrogen from MA1 and MA2, respectively. Due to, Ti, Ni,Y alloying, the decrease in the thermodynamic stability of MgH2 is not found.

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Effect of Al, Fe Addition on Thermodynamic Stability and Hydrogen Desorption KInetics from MgH2 Phase OF Mechanical Alloy

Фізика і хімія твердого тіла ◽

10.15330/pcss.16.3.576-585 ◽

2015 ◽

Vol 16 (3) ◽

pp. 576-585 ◽

Cited By ~ 1

Author(s):

О.G. Еrshova ◽

A.Yu. Koval ◽

Yu.М. Solonin ◽

V.D. Dobrovolsky

Keyword(s):

Mechanical Alloy ◽

Mechanochemical Synthesis ◽

Thermodynamic Stability ◽

Thermal Desorption Spectroscopy ◽

Hydrogen Desorption ◽

Hydrogen Atmosphere ◽

Desorption Kinetics ◽

Reactive Milling ◽

Kinetics Of ◽

Complex Doping

With the aim of lowering the temperature, improve the kinetics of the decomposition of stoichiometric hydride MgH2 was investigated the possibility of its complex doping Al, Fe using mechanochemical synthesis (RMS). The MA1 sample was derived by reactive milling Mg + 10 wt% Al + 10 wt. % Fe powder mixture in the hydrogen atmosphere at pressure of 1.2 MPa in a reactor for 10 h. The formation (in conditions of mechanochemical synthesis) of hydride of solid solution of Al and Fe in magnesium Mg(Al,Fe)H2 was experimentally checked. Found that adding to magnesium Al & Fe leads to lower of thermodynamic stability and, consequently, to lower the temperature of the beginning of desorption of hydrogen to 250 0C at 0,1MPa H2 (compared to MgH2 without Al and Fe). After the first cycles of hydrogenation-dehydrogenation from gas phase MA, established by isobaric thermal desorption spectroscopy, the effect of lowering the temperature of the beginning desorbtion 315 0C (for non-alloy phase MgH2) to 250 0C was observed. Adding to magnesium aluminum with Fe significantly improves the kinetics of desorption of hydrogen from the hydride phase MgH2 mechanical alloy produced by RMS.

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Hydrogen Sorption Properties, Thermal Stability and Kinetics of Hydrogen Desorption from MgH$_2$ Hydride Phase of a Mechanical Alloy of Magnesium with Ti and Y

METALLOFIZIKA I NOVEISHIE TEKHNOLOGII ◽

10.15407/mfint.41.08.0981 ◽

2019 ◽

Vol 41 (8) ◽

pp. 981-1001 ◽

Cited By ~ 1

Author(s):

O. G. Ershova ◽

◽

V. D. Dobrovolsky ◽

Yu. M. Solonin ◽

A. Yu. Koval ◽

...

Keyword(s):

Thermal Stability ◽

Mechanical Alloy ◽

Hydrogen Desorption ◽

Sorption Properties ◽

Hydrogen Sorption ◽

Hydride Phase ◽

Kinetics Of

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The Ordered Phase Formation in Ti-Al-Ga Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069193 ◽

1970 ◽

Vol 28 ◽

pp. 440-441

Author(s):

Shiro Fujishiro ◽

Harold L. Gegel

Keyword(s):

Thermal Stability ◽

High Temperature ◽

Titanium Alloys ◽

Growth Kinetics ◽

Stoichiometric Composition ◽

Good Potential ◽

Alpha Titanium ◽

Cold Rolled ◽

Kinetics Of ◽

Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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Isothermal Vulcanization and Non-Isothermal Degradation Kinetics of XNBR/Epoxy/XNBR-g-Halloysite Nanotubes (HNT) Nanocomposites

Materials ◽

10.3390/ma14112872 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2872

Author(s):

Seyed Mohamad Reza Paran ◽

Ghasem Naderi ◽

Elnaz Movahedifar ◽

Maryam Jouyandeh ◽

Krzysztof Formela ◽

...

Keyword(s):

Thermal Stability ◽

Degradation Kinetics ◽

Halloysite Nanotubes ◽

Butadiene Rubber ◽

Order Model ◽

Scanning Calorimetry ◽

Theoretical Methods ◽

Vulcanization Kinetics ◽

Kinetics Of ◽

Thermal Stability Of

The effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the nth order model could not accurately predict the curing performance. However, the autocatalytic approach can be used to estimate the vulcanization reaction mechanism of XNBR/epoxy/XHNTs nanocomposites. The kinetic parameters related to the degradation of XNBR/epoxy/XHNTs nanocomposites were also assessed using thermogravimetric analysis (TGA). TGA measurements suggested that the grafted nanotubes strongly enhanced the thermal stability of the nanocomposite.

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Thermal Breakdown Kinetics of 1-Ethyl-3-Methylimidazolium Ethylsulfate Measured Using Quantitative Infrared Spectroscopy

Applied Spectroscopy ◽

10.1177/0003702817727293 ◽

2017 ◽

Vol 71 (12) ◽

pp. 2626-2631 ◽

Cited By ~ 1

Author(s):

Jeffrey L. Wheeler ◽

McKinley Pugh ◽

S. Jake Atkins ◽

Jason M. Porter

Keyword(s):

Thermal Stability ◽

Room Temperature ◽

Computational Models ◽

Elevated Temperatures ◽

Molar Absorptivity ◽

Ir Absorption ◽

Optical Cell ◽

Multiple Samples ◽

Kinetics Of ◽

Thermal Stability Of

In this work, the thermal stability of the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) is investigated using infrared (IR) spectroscopy. Quantitative IR absorption spectral data are measured for heated [EMIM][EtSO4]. Spectra have been collected between 25 ℃ and 100 ℃ using a heated optical cell. Multiple samples and cell pathlengths are used to determine quantitative values for the molar absorptivity of [EMIM][EtSO4]. These results are compared to previous computational models of the ion pair. These quantitative spectra are used to measure the rate of thermal decomposition of [EMIM][EtSO4] at elevated temperatures. The spectroscopic measurements of the rate of decomposition show that thermogravimetric methods overestimate the thermal stability of [EMIM][EtSO4].

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