scholarly journals OXIDATION KINETICS OF ALUMINUM ALLOY AK12M2, MODIFIED BY BARIUM, IN SOLID STATE

2020 ◽  
Vol 55 ◽  
pp. 28-33
Author(s):  
Izatuiio. N. Ganiev ◽  
◽  
Furkatshokh Sh. Zokirov ◽  
Murodali M. Sangov ◽  
Asadkul E. Berdiyev ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Solid State ◽  
Oxidation Kinetics ◽  
Alkaline Earth ◽  
Oxidation Process ◽  
Dominant Role ◽  
Alkaline Earth Metals ◽  
Protective Properties ◽  
Initial Alloy ◽  
Kinetics Of

The oxidation kinetics of the AK12M2 aluminum alloy modified to 1.0% by barium was studied using thermogravimetry method. It was shown that the addition of barium to the alloy and the increase in temperature increase the oxidation rate of the initial alloy in the solid state. The apparent activation energy of the oxidation process of the AK12M2 aluminum alloy is 127.73 kJ/mol and decreases to 71.85 kJ∕mol for the alloy with 1.0% barium. The oxidation curves of the AK12M2 aluminum alloy with barium in the solid state are described by polynomials indicating the hyperbolic mechanism of that process. The mechanism of influence of barium on the oxidability of the AK12M2 aluminum alloy was established. It lies in the fact that barium in the range of 0.3-1.0% plays a dominant role in the formation of an oxide film, which is characterized by low protective properties. Barium influence is explained by its physicochemical properties as one of the alkaline earth metals.

scholarly journals OXIDATION KINETICS OF ALUMINUM ALLOY АЖ2.4М5.3МГ1.1Ц4КР3, ALLOYED WITH TIN, IN SOLID STATE

2021 ◽  
Vol 56 ◽  
pp. 17-22
Author(s):  
Orif Sh. Davlatov ◽  
◽  
Izatullo N. Ganiev ◽  
Haydar Odina Odinazoda ◽  
Safomudin S. Rajabaliev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Aluminum Alloy ◽  
Weight Gain ◽  
Oxidation Kinetics ◽  
Oxidation Process ◽  
Thermogravimetric Method ◽  
Protective Properties ◽  
Initial Alloy ◽  
Kinetics Of ◽  
Improved Characteristics

The purpose of this work was to find out the features of oxidation of the aluminum alloy АЖ2.4М5.3Мг1.1Ц4Кр3 doped with tin and to develop new alloy compositions with improved characteristics. The thermogravimetric method was used to determine the oxidation kinetics of the aluminum alloy АЖ2.4М5.3Мг1.1Ц4Кр3, containing up to 0.5 wt% tin. The results showed that the process of weight gain of alloys during first 15-20 minutes of oxidation grows intensively, and then acquires an almost constant value. Oxide films formed at the beginning of the oxidation process did not possess protective properties, that fact explains an increase in the rate of oxidation of alloys with temperature in the first period. An increase in the rate of oxidation of alloy samples with temperature is noted. As well, the results revealed that tin at concentrations of 0.01 - 0.5 wt.% reduces the oxidability of the initial alloy, which is accompanied by an increase in the apparent activation energy from 82.1 to 104.3 kJ/mol.

Effect of praseodymium on the solid-state oxidation kinetics of an AMg2 alloy

2015 ◽  
Vol 2015 (7) ◽  
pp. 521-524 ◽  
Author(s):  
N. F. Ibrokhimov ◽  
I. N. Ganiev ◽  
A. E. Berdiev ◽  
N. I. Ganieva
Keyword(s):  
Solid State ◽  
Oxidation Kinetics ◽  
Kinetics Of

Microstructure Evolution and Coarsening Mechanism of 7075 Semi-Solid Aluminum Alloy Pre-Deformed by ECAP Method

2016 ◽  
Vol 256 ◽  
pp. 294-300 ◽  
Author(s):  
Jin Long Fu ◽  
Yu Wei Wang ◽  
Kai Kun Wang ◽  
Xiao Wei Li
Keyword(s):  
Aluminum Alloy ◽  
Solid State ◽  
Ostwald Ripening ◽  
Liquid Fraction ◽  
Isothermal Holding ◽  
Angular Pressing ◽  
Average Grain Size ◽  
Semi Solid ◽  
Equiaxed Grains ◽  
Kinetics Of

To investigate the influence of refined grains on the microstructure of 7075 aluminum alloy in semi-solid state, a new strain induced melting activation (SIMA) method was put forward containing two main stages: pre-deformation with equal channel angular pressing (ECAP) method and isothermally holding in the semi-solid temperature range. The breaking up and growth mechanisms of the grains and kinetics of equiaxed grains coarsening during the semi-solid holding were investigated. The results showed that the average grain size after ECAP extrusion decreased significantly, e.g., microstructure with average globular diameter less than 5μm was achieved after four-pass ECAP extrusion. Obvious grain coarsening had been found during isothermal holding in the semi-solid state and the roundness of the grains increased with the increasing holding time. The proper microstructure of 66.8μm in diameter and 1.22 in shape factor was obtained under proper soaking condition (at 590°C for 15 min). Two coarsening mechanisms, namely, coalescence in lower liquid fraction and Ostwald ripening in higher liquid fraction contributed to the grain growth process.

Niobium-bearing arsenides and germanides from elemental mixtures not involving niobium: a new twist to an old problem in solid-state synthesis

2018 ◽  
Vol 74 (5) ◽  
pp. 623-627 ◽  
Author(s):  
Sviatoslav Baranets ◽  
Hua He ◽  
Svilen Bobev
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Diffraction Data ◽  
Alkaline Earth ◽  
Alkaline Earth Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Reactions ◽  
First Time ◽  
Synthetic Work

Three isostructural transition-metal arsenides and germanides, namely niobium nickel arsenide, Nb0.92(1)NiAs, niobium cobalt arsenide, NbCoAs, and niobium nickel germanide, NbNiGe, were obtained as inadvertent side products of high-temperature reactions in sealed niobium containers. In addition to reporting for the very first time the structures of the title compounds, refined from single-crystal X-ray diffraction data, this article also serves as a reminder that niobium containers may not be suitable for the synthesis of ternary arsenides and germanides by traditional high-temperature reactions. Synthetic work involving alkali or alkaline-earth metals, transition or early post-transition metals, and elements from groups 14 or 15 under such conditions may yield Nb-containing products, which at times could be the major products of such reactions.

scholarly journals Solid State Hydrogen Storage in Alanates and Alanate-Based Compounds: A Review

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 567 ◽  
Author(s):  
Chiara Milanese ◽  
Sebastiano Garroni ◽  
Fabiana Gennari ◽  
Amedeo Marini ◽  
Thomas Klassen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Absorption ◽  
Alkaline Earth ◽  
Molecular Form ◽  
Alkaline Earth Metals ◽  
Highly Porous Materials ◽  
Physico Chemical ◽  
Solid Form ◽  
Highly Porous

The safest way to store hydrogen is in solid form, physically entrapped in molecular form in highly porous materials, or chemically bound in atomic form in hydrides. Among the different families of these compounds, alkaline and alkaline earth metals alumino-hydrides (alanates) have been regarded as promising storing media and have been extensively studied since 1997, when Bogdanovic and Schwickardi reported that Ti-doped sodium alanate could be reversibly dehydrogenated under moderate conditions. In this review, the preparative methods; the crystal structure; the physico-chemical and hydrogen absorption-desorption properties of the alanates of Li, Na, K, Ca, Mg, Y, Eu, and Sr; and of some of the most interesting multi-cation alanates will be summarized and discussed. The most promising alanate-based reactive hydride composite (RHC) systems developed in the last few years will also be described and commented on concerning their hydrogen absorption and desorption performance.

scholarly journals Termite pyrotechnic compositions of iron and alkaline earth metals peroxides

2020 ◽  
pp. 55-72
Author(s):  
Andrzej Wojewódka ◽  
Marcin Gerlich
Keyword(s):  
Time Delay ◽  
Solid State ◽  
Alkaline Earth ◽  
Front Propagation ◽  
Xrd Analysis ◽  
Propagation Rate ◽  
Alkaline Earth Metals ◽  
Pyrotechnic Compositions ◽  
Iron Based ◽  
Delay Elements

The fallowing article presents the combustion studies of Fe/alkaline earth metals peroxides composition. It contains a literature review and the results of own research, which aim is to determine the possibility of using iron-based thermite compositions in time delay elements. The article focuses on the investigation of combustion front propagation rate as a function of a pressing load, the iron content and the purity of used oxidants. The DSC, TG and XRD analysis confirmed that reactions in this system occurs mainly in the solid state.

Influence of praseodymium on a solid – State oxidation kinetics of Al + 6%Li alloy

2020 ◽  
Vol 30 ◽  
pp. 628-631
Author(s):  
Sh. Nazarov ◽  
I. Ganiev ◽  
A. Gafarov ◽  
D. Nazarov ◽  
O. Tolochko ◽  
...  
Keyword(s):  
Solid State ◽  
Oxidation Kinetics ◽  
Kinetics Of

Oxidation Kinetics of Cu Alloys Containing Alkaline Earth Metals at Low Temperature

2021 ◽  
Vol 21 (3) ◽  
pp. 2071-2074
Author(s):  
Seong-Ho Ha ◽  
Shah Abdul Wahid ◽  
Bong-Hwan Kim ◽  
Young-Ok Yoon ◽  
Hyun-Kyu Lim ◽  
...  
Keyword(s):  
Master Alloy ◽  
Alkaline Earth ◽  
Oxidation Behavior ◽  
Testing Temperature ◽  
Alkaline Earth Metals ◽  
Alloying Element ◽  
Oxidation Rates ◽  
Cu Alloys ◽  
Mg Addition ◽  
Kinetics Of

In this study, the oxidation behavior of Cu alloys containing two alkaline earth metals (i.e., Mg and Ca) at 500 °C was investigated. The Mg+Mg2Ca master alloy was used for the simultaneous addition of Mg and Ca into Cu. As a result of the oxidation test, all examined samples showed weight gains that followed parabolic laws. Mg addition in Cu considerably slowed down the oxidation rate, while the use of the Mg+Mg2Ca master alloy as an alloying element for Mg led to an even further reduction in the oxidation rates at the testing temperature. The phase diagrams with the oxygen partial pressure showed that the Ca and Mg-containing alloy resulted in the formation of CaO as the primary oxide and MgO as the secondary oxide. The improved oxidation resistance can be attributed to the mixed surface layer of CaO and MgO, which control the growth rate of Cu2O.

Oxidation kinetics of Pb–Sn alloys

1989 ◽  
Vol 4 (6) ◽  
pp. 1421-1426 ◽  
Author(s):  
R. A. Konetzki ◽  
Y. A. Chang ◽  
V. C. Marcotte
Keyword(s):  
Solid State ◽  
Auger Electron Spectroscopy ◽  
Oxidation Kinetics ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Single Phase ◽  
Depth Profiling ◽  
Eutectic Alloys ◽  
Parabolic Oxidation ◽  
Kinetics Of

The solid state oxidation kinetics of Pb–Sn single-phase (2.5 at. % Sn) and eutectic alloys were studied with Auger Electron Spectroscopy combined with sputter depth profiling. The single-phase samples were oxidized in air in the temperature range 22 °C to 250 °C, while the eutectic samples were oxidized from 22 °C to 175 °C. Both alloys oxidize logarithmically between 22 °C and 90 °C and parabolically at temperatures greater than 120 °C. The activation energies for the parabolic oxidation of the single-phase and eutectic alloys are 69.5 and 67.1 ± 8 kJ/mole, respectively.

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