Kinetics of bayerite microstructure formation from powdered aluminum

2008 ◽  
Vol 70 (2) ◽  
pp. 210-214 ◽  
Author(s):  
A. I. Rat’ko ◽  
T. F. Kuznetsova ◽  
V. E. Romanenkov ◽  
D. I. Klevchenya
Keyword(s):  
Microstructure Formation ◽  
Powdered Aluminum ◽  
Kinetics Of

Kinetics of the microstructure formation in a rapid solidified immiscible alloy

2008 ◽  
Vol 44 (2) ◽  
pp. 400-403 ◽  
Author(s):  
Jiuzhou Zhao ◽  
Haili Li ◽  
Qingliang Wang ◽  
Jie He
Keyword(s):  
Microstructure Formation ◽  
Immiscible Alloy ◽  
Kinetics Of

scholarly journals Change of the kinetics of solidification and microstructure formation induced by convection in the Ni–Al system

2007 ◽  
Vol 91 (4) ◽  
pp. 041913 ◽  
Author(s):  
S. Reutzel ◽  
H. Hartmann ◽  
P. K. Galenko ◽  
S. Schneider ◽  
D. M. Herlach
Keyword(s):  
Microstructure Formation ◽  
Kinetics Of

Microstructure Formation in Cast β-Solidifying γ-Titanium Aluminide Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 1394-1399 ◽  
Author(s):  
Michael Oehring ◽  
Fritz Appel ◽  
Jonathan H.D. Paul ◽  
Renat M. Imayev ◽  
V.M. Imayev ◽  
...  
Keyword(s):  
Titanium Aluminide ◽  
Microstructure Formation ◽  
State Transformation ◽  
Solid State Transformation ◽  
Alloying Effect ◽  
Microstructural Refinement ◽  
Nucleation Sites ◽  
Cast Alloys ◽  
Titanium Aluminide Alloys ◽  
Kinetics Of

In view of the development of improved TiAl cast alloys the potential of the  transformation and its dependence on the addition of several alloying elements has been investigated. It was found that microstructural refinement in  solidifying alloys can be attributed to the alloying effect on the kinetics of the  transformation. This also holds for grain refinement through Borides which apparently serve as nucleation sites for the  phase in the solid-state transformation.

Studying the kinetics of microstructure formation through dewetting of As-Se thin films

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Y. N. Colmenares ◽  
Sandra Helena Messaddeq ◽  
Younès Messaddeq
Keyword(s):  
Thin Films ◽  
Microstructure Formation ◽  
Kinetics Of

Influence of a Direct Current on the Solidification of Immiscible Alloys

2016 ◽  
Vol 879 ◽  
pp. 2479-2484 ◽  
Author(s):  
Hong Xiang Jiang ◽  
Qian Sun ◽  
Jiu Zhou Zhao
Keyword(s):  
Direct Current ◽  
Current Density ◽  
Radial Component ◽  
Core Shell ◽  
Microstructure Development ◽  
Shell Microstructure ◽  
Microstructure Formation ◽  
Immiscible Alloys ◽  
Minority Phase ◽  
Kinetics Of

Continuous solidification experiments were carried out with immiscible alloys under the effect of a direct current. The experimental results demonstrate that a direct current shows a significant effect on the migration of minority phase droplets (MPDs) in continuously solidified immiscible alloys. It can promote the formation of a well dispersed microstructure or a core/shell microstructure. A model describing the kinetics of the microstructure evolution in a continuously solidified immiscible alloy was developed. The microstructure formation in the alloys was calculated. The numerical results are in favorable agreement with the experimental ones. They demonstrate that a direct current may affect the microstructure development through changing the spatial motions of MPDs. The alloys show a well dispersed microstructure when they are solidified with such a direct current density that the direct current causing motion of the MPDs is almost equivalent to the radial component of the Marangoni migration velocity of the MPDs. The alloys show a core/shell microstructure when they are solidified with such a direct current density that the direct current causing motion of the MPDs dominates the migration of the MPDs along the radial direction of the sample. A wire or rod with well dispersed microstructure or a core/shell microstructure can be prepared by solidifying immiscible alloys under the effect of a direct current properly chosen.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

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