Kinetics of intermetallic compound layers during initial period of reaction between mild steel and molten aluminum

2019 ◽  
Author(s):  
Huan He ◽  
Wenqin Gou ◽  
Shengxiang Wang ◽  
Yu Hou ◽  
Chao Ma ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Mild Steel ◽  
Molten Aluminum ◽  
Initial Period ◽  
Kinetics Of

The mechanism of the anionic coordination polymerization of isoprene

1980 ◽  
Vol 45 (9) ◽  
pp. 2391-2399 ◽  
Author(s):  
Miroslav Kašpar ◽  
Jiří Trekoval
Keyword(s):  
Chromatographic Method ◽  
Initial Period ◽  
Reaction Scheme ◽  
Polymerization Kinetics ◽  
Coordination Polymerization ◽  
Initial Concentration ◽  
The Cross ◽  
Gas Chromatographic Method ◽  
Kinetics Of

The polymerization kinetics of isoprene (2-methyl-1,3-butadiene) in benzene with butyllithium as the initiator was investigated by the gas chromatographic method. After completion of the initial period of the reaction, its order with respect to the initial concentration of initiator is negative at the concentrations of the latter between 0.01 and 0.25 mol/l, and positive at higher concentrations. A reaction scheme has been suggested with respect to the "cross" association of butyllithium and of the "living" oligoisoprene.

Vulcanization of Rubber in the Presence of N,N-Diethyl-2-Benzothiazolylsulfenamide as Accelerator

1960 ◽  
Vol 33 (2) ◽  
pp. 361-372 ◽  
Author(s):  
B. A. Dogadkin ◽  
O. N. Beliatskaya ◽  
A. B. Dobromyslova ◽  
M. S. Feldshtein
Keyword(s):  
Induction Period ◽  
Maximum Rate ◽  
Initial Period ◽  
Pure Oxygen ◽  
Butadiene Rubber ◽  
Sulfur Vulcanization ◽  
Analogous Manner ◽  
Chemical Crosslinks ◽  
Main Period ◽  
Kinetics Of

Abstract 1. The vulcanization of rubber in the presence of N,N-diethyl-2-benzothiazolylsulfenamide is characterized by an S-shaped curve for the addition of sulfur with an initial induction period in the reaction. The modulus and number of crosslinks are changed in an analogous manner to the structure of the vulcanizate. 2. The energy of activation of the addition of sulfur in the initial period is equal to 30 kcal per mole as against 14 kcal per mole in the main period. 3. The induction period is increased if the sodium-butadiene rubber is purified from alkali. 4. Molecular oxygen present in the compound being vulcanized decreases the induction period and increases the rate of the addition of the sulfur in the main period. An induction period is not observed when vulcanization is carried out in an atmosphere of pure oxygen. 5. The interaction of N,N-diethyl-2-benzothiazolylsulfenamide with rubber (in the absence of sulfur) at vulcanization temperatures is accompanied by the formation of MBT, diethylamine, and the addition of the elements of the accelerator to the rubber. The kinetics of this process were studied. 6. The interaction of N,N-diethyl-2-benzothiazolyl sulfenamide with rubber leads to the formation of chemical crosslinks between the molecules of rubber (the effect of vulcanization). 7. The change of N,N-diethyl-2-benzothiazolyl sulfenamide under the conditions of normal sulfur vulcanization has the same character as in the interaction of it with rubber. The kinetics of the formation of MBT have a maximum which coincides with the maximum rate of the addition of sulfur to the rubber. 8. A mechanism is presented for the vulcanization and acceleration actions of N,N-diethyl-2-benzothiazolyl sulfenamide which provides for the extraction of hydrogen by the accelerator radicals from the molecular chains of the rubber with the formation of MBT, diethylamine and polymer radicals which are able to interact with the sulfur.

scholarly journals Growth kinetics of antiphase domain in Ti3Al intermetallic compound

2004 ◽  
Vol 5 (1-2) ◽  
pp. 19-28 ◽  
Author(s):  
Y. Koizumi ◽  
H. Katsumura ◽  
Y. Minamino ◽  
N. Tsuji ◽  
J.G. Lee ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Growth Kinetics ◽  
Antiphase Domain ◽  
Kinetics Of

scholarly journals Comparing hydrogen absorption kinetics of the samples of intermetallic compound and metal hydride compact on its basis

2021 ◽  
Vol 2057 (1) ◽  
pp. 012043
Author(s):  
I A Romanov ◽  
V I Borzenko ◽  
A N Kazakov
Keyword(s):  
Intermetallic Compound ◽  
Metal Hydride ◽  
Hydrogen Absorption ◽  
Reaction Rate ◽  
Nickel Foam ◽  
High Confidence ◽  
Compact Sample ◽  
Kinetics Of ◽  
Rate Controlling Step ◽  
Absorption Of Hydrogen

Abstract This work is devoted to an experimental study and comparison of the kinetics of hydrogen absorption by an intermetallic compound LaNi4.4Al0.3Fe0.3 in form of pure intermetallic compound free backfill and a compact based on it obtained by cold pressing with a spiral matrix of nickel-foam. To calculate the kinetic parameters of the hydrogen absorption reaction, the initial rates method is used. The PCT absorption isotherms are measured at temperatures of 313, 333, and 353 K. The experimental data are described with quite high confidence by the chosen model, which assumes that the reaction rate controlling step is the dissociative absorption of hydrogen on the surface of the a-phase. The rate of hydrogen absorption increases with increasing pressure drop and temperature. It is shown that the rate of hydrogen absorption by the sample of pure IMC is significantly less dependent on temperature compared to the compact sample. In addition, the reaction rate at temperatures of 313 and 333 K is higher for the free backfill sample, and at 353 K it is higher for the metal hydride compact. The values of the absorption constant and the activation energy of the hydrogen absorption reaction are determined for both samples.

scholarly journals Effect of Degassing Treatment on the Interfacial Reaction of Molten Aluminum and Solid Steel

2017 ◽  
Vol 17 (2) ◽  
pp. 227-239 ◽  
Author(s):  
T. Triyono ◽  
N. Muhayat ◽  
A. Supriyanto ◽  
L. Lutiyatmi
Keyword(s):  
Electron Microscope ◽  
Intermetallic Compound ◽  
Scanning Electron Microscope ◽  
Interfacial Reaction ◽  
Immersion Time ◽  
Molten Aluminum ◽  
Furnace Lining ◽  
Brittle Phase ◽  
Crucible Furnace ◽  
Scanning Electron

AbstractThe gas porosity is one of the most serious problems in the casting of aluminum. There are several degassing methods that have been studied. During smelting of aluminum, the intermetallic compound (IMC) may be formed at the interface between molten aluminum and solid steel of crucible furnace lining. In this study, the effect of degassing treatment on the formations of IMC has been investigated. The rectangular substrate specimens were immersed in a molten aluminum bath. The holding times of the substrate immersions were in the range from 300 s to 1500 s. Two degassing treatments, argon degassing and hexachloroethane tablet degassing, were conducted to investigate their effect on the IMC formation. The IMC was examined under scanning electron microscope with EDX attachment. The thickness of the IMC layer increased with increasing immersion time for all treatments. Due to the high content of hydrogen, substrate specimens immersed in molten aluminum without degasser had IMC layer which was thicker than others. Argon degassing treatment was more effective than tablet degassing to reduce the IMC growth. Furthermore, the hard and brittle phase of IMC, FeAl3, was formed dominantly in specimens immersed for 900 s without degasser while in argon and tablet degasser specimens, it was formed partially.

scholarly journals Estimation of anti-icing properties of coatings

2019 ◽  
Vol 135 ◽  
pp. 01009
Author(s):  
Valentina Loganina ◽  
Svetlana Kislitsyna
Keyword(s):  
Initial Period ◽  
Wetting Angle ◽  
Silicone Resin ◽  
Thermal Imager ◽  
Freezing Front ◽  
Properties Of Coatings ◽  
Metal Structures ◽  
Wetting Hysteresis ◽  
Inclined Surface ◽  
Kinetics Of

The proposed composition for anti-icing coating of metal structures. The composition contains as the filler used aerosil brand R 972 with a density of 2360 kg / m3, particle size of 16 nm and a specific surface 12000 m2 / kg. Silicone resin SILRES® MSE 100 with a 10% concentration was used as a binder. The degree of hydrophobicity was estimated by the value of the wetting angle. In order to characterize the anti-icing properties of the coatings, we used the static and dynamic (advancing and retreating) wetting angle, as well as wetting hysteresis, for which we measured the angles of leakage, and the angles of drift from. Studies of the dynamics of freezing drops on the surface were performed using a TESTO 875-1 thermal imager. It is shown, that the hysteresis of wetting of the superhydrophobic surface based on the developed composition is 3.7 degrees. The critical angle of rolling drops of water from an inclined surface is determined. In the study of the kinetics of freezing of a drop of water on a metal surface, an uneven distribution of temperature on the surface of a drop of water is observed. The process of freezing drops is multistage. In the initial period, there is a transfer of heat from the surface to a drop of water. This stage is followed by the process of freezing the drop, which is manifested in the movement of the freezing front from the substrate upwards.

Kinetics of intermetallic compound layers and Cu dissolution at Sn1.5Cu/Cu interface under high magnetic field

2010 ◽  
Vol 25 (2) ◽  
pp. 359-367 ◽  
Author(s):  
Cong-qian Cheng ◽  
Jie Zhao ◽  
Yang Xu
Keyword(s):  
Magnetic Field ◽  
Intermetallic Compound ◽  
Lorentz Force ◽  
High Magnetic Field ◽  
Solubility Limit ◽  
Layer Growth ◽  
Ripening Process ◽  
Cu Substrate ◽  
Cu Dissolution ◽  
Kinetics Of

The kinetics of intermetallic compound (IMC) layer and Cu dissolution at Sn1.5Cu/Cu interface under high magnetic field was experimentally examined. It is found that the IMC layer growth is controlled by flux-driven ripening process. The high magnetic field promotes the growth of IMC layer, retards the dissolution of Cu substrate, and decreases the content of Cu solute at the liquid–IMC interface front. Based on the experimental results, it is considered that the magnetization induced by magnetic field promotes the ripening process for IMC layer growth. The Lorentz force dampening the convection and magnetization decreasing the Cu solubility limit can retard the Cu dissolution and change the solute distribution at the liquid–IMC interface front.

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