scholarly journals Numerical simulation of an equilibrium segregation of impurities on the grain boundaries of copper and its alloys

2017 ◽  
Vol 51 (3) ◽  
pp. 363-372
Author(s):  
W. Ozgowicz
Keyword(s):  
Numerical Simulation ◽  
Grain Boundaries ◽  
Segregation Of Impurities ◽  
Equilibrium Segregation

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).

Non-equilibrium segregation of boron at austenite grain boundaries

1991 ◽  
Vol 10 (20) ◽  
pp. 1232-1234 ◽  
Author(s):  
Shenhua Song ◽  
Zhexi Yuan ◽  
Tingdong Xu
Keyword(s):  
Grain Boundaries ◽  
Austenite Grain ◽  
Equilibrium Segregation ◽  
Non Equilibrium

EFFECT OF SMALL BULK SULFUR CONTENT AND ANNEALING TEMPERATURE ON THE INTERGRANULAR FRACTURING SUSCEPTIBILITY OF METALLIC NICKEL

2016 ◽  
Vol 23 (06) ◽  
pp. 1650050 ◽  
Author(s):  
BOUTASSOUNA DJAMAL ◽  
RENÉ LE GALL ◽  
IBEN KHALDOUN LEFKAIER
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Sulfur Content ◽  
Auger Spectroscopy ◽  
Metallic Nickel ◽  
Boundary Equilibrium ◽  
Influence Of Temperature On ◽  
Sulfide Compound ◽  
Equilibrium Segregation

In this paper, we investigate the influence of temperature on the nickel grain boundary equilibrium segregation of sulfur and the resulting intergranular fracturing susceptibility. Auger electron spectroscopy has been used to study equilibrium segregation of sulfur to the grain boundaries of a metallic nickel, with a mass bulk content of 3.6[Formula: see text]ppm in sulfur. Samples were first annealed at adequate temperatures for sufficiently large equilibrium time, and then quenched in water at room temperature. The analysis carried out shows a significant increase of sulfur concentration in the grain boundary with decreasing temperature. However, the sulfur content in the grain boundary shows a drastic shrink at 700[Formula: see text]C. This can be interpreted by the formation of an aggregate sulfide compound in the area of the grain boundaries. At 650[Formula: see text]C, in situ brittle fracture becomes unworkable and only intragranular fractures are observed. Using the results obtained through the investigation of the grain boundaries by Auger spectroscopy, the standard segregation energy is estimated as [Formula: see text].

Segregation of Impurities at Grain Boundaries and Other Compositional Inhomogeneities in Chill-Casted Silicon Ingots

1982 ◽  
pp. 874-882 ◽  
Author(s):  
S. Pizzini ◽  
L. Braicovich° ◽  
L. Calliari ◽  
M. Gasparini ◽  
C. M. Mari ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Segregation Of Impurities

The “Solidification” of Grain Boundaries with Increasing Temperature

1994 ◽  
Vol 357 ◽  
Author(s):  
Witold Lojkowski ◽  
Bogdan Palosz
Keyword(s):  
Solid State ◽  
Melting Point ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
High Temperatures ◽  
Low Temperatures ◽  
Melting Behavior ◽  
Wetting Transitions ◽  
Increasing Temperature ◽  
Segregation Of Impurities

AbstractThe aim of the paper is to explain the recently observed de-wetting grain boundary transition with increasing temperature. On the example of a bicrystal from the Fe-6at.%Si alloy, it was found recently that as temperature is increased, the following GB transitions take place: “solid” (or regular) GB-→“premelted” GB →“solid” GB. At the same time the wetting/de-wetting transitions have taken place. Another example of such GB behavior was discovered during sintering of alumina. The inverse melting behavior is explained as follows: low melting point impurities cause GB premelting at low temperatures, However de-segregation of impurities at high temperatures causes return of the GB structure to its regular “solid” state.

A New Model for Simulating AC and Surge Properties of ZnO Varistors Based on Microstructural Characteristics

2008 ◽  
Vol 368-372 ◽  
pp. 510-513 ◽  
Author(s):  
Jun Hu ◽  
Jin Liang He ◽  
Feng Chao Luo
Keyword(s):  
Numerical Simulation ◽  
Grain Boundaries ◽  
Conduction Mechanism ◽  
Piecewise Linear ◽  
Linear Method ◽  
Microstructural Characteristics ◽  
Nonlinear Resistor ◽  
Resistor Networks ◽  
Zno Varistors ◽  
The Relationship

The numerical simulation is an effective method for researching the relationship between macroscopic properties of ZnO varistors and their microstructural characteristics. However, the computing efficiency is a big problem for further researches. In this paper, a quick piecewise linear method for solving the complicated nonlinear resistor networks of ZnO varistors is proposed, which can significantly improve the computing efficiency by a hundred times. The simulating models for the microstructural characteristics of ZnO varistors are improved based on actual conduction mechanism of grain boundaries. The simulations of more bulk characteristics of ZnO varistors become possible, such as alternating current (AC) and surge properties.

scholarly journals Cooperative chemical rebonding in the segregation of impurities in silicon grain boundaries

1996 ◽  
Author(s):  
A. Maiti ◽  
M.F. Chisholm ◽  
S.J. Pennycook ◽  
S.T. Pantelides
Keyword(s):  
Grain Boundaries ◽  
Segregation Of Impurities
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