scholarly journals Transmittance and Reflectance of an Imprinted Cholesteric Elastomer During a Segregation Process

10.5772/50747 ◽  
2012 ◽  
Author(s):  
P. Castro-Garay ◽  
Jesus Manzanares-Martinez
Keyword(s):  
Segregation Process

Measurement of solute segregation to grain boundaries in the AEM: A review

1988 ◽  
Vol 46 ◽  
pp. 606-607
Author(s):  
D. B. Williams ◽  
A. D. Romig
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Boundary Misorientation ◽  
Collector Plate ◽  
Segregation Process ◽  
Grain Boundary Misorientation ◽  
Structure Boundary ◽  
Equilibrium Segregation

The segregation of solute or imparity elements to grain boundaries can occur by three well-defined processes. The first is Gibbsian segregation in which an element of minimal matrix solubility confines itself to a monolayer at the grain boundary. Classical examples include Bi in Cu and S or P in Fe. The second process involves the depletion of excess matrix solute by volume diffusion to the boundary. In the boundary, the solute atoms diffuse rapidly to precipitates, causing them to grow by the ‘collector-plate mechanism.’ Such grain boundary diffusion is thought to initiate “Diffusion-Induced Grain Boundary Migration,” (DIGM). This process has been proposed as the origin of eutectoid transformations or discontinuous grain boundary reactions. The third segregation process is non-equilibrium segregation which result in a solute build-up around the boundary because of solute-vacancy interactions.All of these segregation phenomena usually occur on a sub-micron scale and are often affected by the nature of the grain boundary (misorientation, defect structure, boundary plane).

Is it a Right Assumption That B and Ge are Distributed Randomly After Growing a Strained HBT-Structure?

2002 ◽  
Vol 716 ◽  
Author(s):  
Victor I. Kol'dyaev
Keyword(s):  
Surface Segregation ◽  
Initial Conditions ◽  
Initial Condition ◽  
Basic Assumptions ◽  
Transient Diffusion ◽  
Segregation Process ◽  
Main Observation

AbstractIt is accepted that surface Ge atoms are considered to be responsible for the surface B segregation process. A set of original experiments is carried out. A main observation from the B and Ge profiles grown at different conditions shows that at certain conditions B is taking initiative and determine the Ge surface segregation process. basic assumptions are suggested to self-consistently explain these original experimental features and what is observed in the literature. These results have a strong implication for modeling the B diffusion in Si1-xGex where the initial conditions should be formulated accounting for the correlation in B and Ge distribution. A new assumption for the initial condition to be “all B atoms are captured by Ge” is regarded as a right one implicating that there is no any transient diffusion representing the B capturing kinetics.

Unsteady 3D and analytical analysis of segregation process in floating zone silicon single crystal growth

2009 ◽  
Vol 45 (4) ◽  
pp. 549-556 ◽  
Author(s):  
K. Lācis ◽  
◽  
A. Muižnieks ◽  
N. Jēkabsons ◽  
A. Rudevičs ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystal Growth ◽  
Silicon Single Crystal ◽  
Floating Zone ◽  
Analytical Analysis ◽  
Segregation Process

Effects of surface chemical potentials on cation segregation

2021 ◽  
Author(s):  
Eugene Ostrovskiy ◽  
Yi-Lin Huang ◽  
Eric D. Wachsman
Keyword(s):  
Surface Chemical ◽  
Chemical Potentials ◽  
Segregation Process ◽  
Gas Molecules

The presence of gas molecules alters the surface cation segregation process on perovskites.

Flow visualization of segregation process in a fluidized-bed by neutron radiography

2005 ◽  
Vol 52 (1) ◽  
pp. 295-298
Author(s):  
S. Furui ◽  
H. Umekawa ◽  
K. Hayashi ◽  
M. Ozawa ◽  
N. Takenaka
Keyword(s):  
Flow Visualization ◽  
Fluidized Bed ◽  
Neutron Radiography ◽  
Segregation Process

CYCLIC SEGREGATION STATE IN VERTICALLY VIBRATED BINARY GRANULAR MIXTURES

2014 ◽  
Vol 28 (03) ◽  
pp. 1450020
Author(s):  
QINGFAN SHI ◽  
BEICHENG PAN ◽  
CHANGHONG LU ◽  
GANG SUN
Keyword(s):  
Phase Diagram ◽  
Atmospheric Pressure ◽  
Air Flow ◽  
Brazil Nut ◽  
Positive Role ◽  
Structure Changes ◽  
Granular Mixtures ◽  
Segregation Process ◽  
Acceleration Amplitude ◽  
Brazil Nut Effect

In this paper, the vertically vibrated binary granular mixtures at atmospheric pressure are studied experimentally. We find a nonstationary segregation state, of which the structure changes with time cyclically. The period of the cyclic segregation is measured and its variation with the vibration conditions is shown. The transition between the segregation states is also discussed, and a phase diagram on the plot of frequency against acceleration amplitude is given. In order to observe the effect of air flow in the segregation process, an alternative container with ventilated bottom is designed. Our experiments show that both regions of the Brazil nut segregation state and the cyclic segregation state shrink obviously by use of the latter container and disappear completely if the whole system is placed in vacuum. These results testify that the air pressure plays a positive role in both the Brazil nut effect and cyclic segregation.

scholarly journals Influences of CO2 on the Microstructure in Sheared Olivine Aggregates

2021 ◽  
Author(s):  
Huihui Zhang ◽  
Ningli Zhao ◽  
Chao Qi ◽  
Xiaoge Huang ◽  
Greg Hirth
Keyword(s):  
Olivine Basalt ◽  
Fluid Phase ◽  
Shear Plane ◽  
Formation Model ◽  
Two Phase ◽  
Experimental Conditions ◽  
Crystallographic Preferred Orientation ◽  
Segregation Process ◽  
Basaltic Melt ◽  
Carbonate Melt

Shear deformation of a solid-fluid, two-phase material induces a fluid segregation process that produces fluid-enriched bands and fluid-depleted regions, and crystallographic preferred orientation (CPO) characterized by girdles of [100] and [001] axes sub-parallel to the shear plane and a cluster of [010] axes sub-normal to the shear plane, namely the AG-type fabric. Based on experiments of two-phase aggregates of olivine + basalt, a two-phase flow theory and a CPO-formation model were established to explain these microstructures. Here, we investigate the microstructure in a two-phase aggregate with supercritical CO2 as the fluid phase and examine the theory and model, as CO2 is different from basaltic melt in rheological properties. We conducted high‐temperature and high-pressure shear deformed experiments at 1 GPa and 1100ºC in a Griggs-type apparatus on samples made of olivine + dolomite, which decomposed into carbonate melt and CO2 at experimental conditions. After deformation, CO2 segregation and an AG-type fabric occurred in these CO2-bearing samples, inconsistency with basaltic melt-bearing samples. The SPO-induce CPO model was used to explain the formation of the fabric. Our results suggest that the influences of CO2 as a fluid phase on the microstructure of a two-phase olivine aggregate is similar to that of basaltic melt and can be explained by the CPO-formation model for the solid-fluid system.

Physical and Mechanical Properties of Composites with Aluminum Alloy Matrix Designed for Metal Forming

2013 ◽  
Vol 212 ◽  
pp. 59-62 ◽  
Author(s):  
Jerzy Myalski ◽  
Jakub Wieczorek ◽  
Adam Płachta
Keyword(s):  
Mechanical Properties ◽  
Metal Forming ◽  
Matrix Material ◽  
Physical And Mechanical Properties ◽  
Mechanical Mixing ◽  
Alloy Matrix ◽  
Segregation Process ◽  
The Matrix ◽  
Glass Carbon ◽  
Properties Of Composites

The change of matrix and usage of the aluminum alloys designed for the metal forming in making the composite suspension allows to extend the processing possibility of this type of materials. The possibility of the metal forming of the composites obtained by mechanical mixing will extend the range of composite materials usage. Applying of the metal forming e.g. matrix forging, embossing, pressing or rolling, will allow to remove the incoherence of the structure created while casting and removing casting failures. In order to avoid the appearance of the casting failures the homogenization conditions need to be changed. Inserting the particles into the matrix influences on the shortening of the composite solidification. The type of the applied particles influenced the sedimentation process and reinforcement agglomeration in the structure of the composite. Opposite to the composites reinforced with one-phase particles applying the fasess mixture (glassy carbon and silicon carbide) triggered significant limitation in the segregation process while casting solidification. Inserting the particles into the AW-AlCu2SiMn matrix lowers the mechanical properties tension and impact value strength. The most beneficial mechanical properties were gained in case of heterofasess composites reinforced with the particle mixture of SiC and glass carbon. The chemical composition of the matrix material (AW-AlCu2SiMn) allows to increase additionally mechanical characteristics by the precipitation hardening reached through heat casting forming.

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