Direct measurement of non-equilibrium solute segregation to grain boundaries

1969 ◽  
Vol 3 (9) ◽  
pp. 663-665 ◽  
Author(s):  
S.J. Bercovici ◽  
P. Niessen ◽  
J.J. Byerley
Author(s):  
J. R. Michael ◽  
C. H. Lin ◽  
S. L. Sass

The segregation of solute atoms to grain boundaries in polycrystalline solids can be responsible for embrittlement of the grain boundaries. Although Auger electron spectroscopy (AES) and analytical electron microscopy (AEM) have verified the occurrence of solute segregation to grain boundaries, there has been little experimental evidence concerning the distribution of the solute within the plane of the interface. Sickafus and Sass showed that Au segregation causes a change in the primary dislocation structure of small angle [001] twist boundaries in Fe. The bicrystal specimens used in their work, which contain periodic arrays of dislocations to which Au is segregated, provide an excellent opportunity to study the distribution of Au within the boundary by AEM.The thin film Fe-0.8 at% Au bicrystals (composition determined by Rutherford backscattering spectroscopy), ∼60 nm thick, containing [001] twist boundaries were prepared as described previously. The bicrystals were analyzed in a Vacuum Generators HB-501 AEM with a field emission electron source and a Link Analytical windowless x-ray detector.


1991 ◽  
Vol 10 (20) ◽  
pp. 1232-1234 ◽  
Author(s):  
Shenhua Song ◽  
Zhexi Yuan ◽  
Tingdong Xu

2016 ◽  
Vol 6 (3) ◽  
pp. 183-188 ◽  
Author(s):  
D. V. Bachurin ◽  
R. T. Murzaev ◽  
J. A. Baimova ◽  
A. A. Samigullina ◽  
K. A. Krylova

1970 ◽  
Vol 9 (55) ◽  
pp. 117-124 ◽  
Author(s):  
Yukiko Mizuno ◽  
Daisuke Kuroiwa

Abstract Segregation of chemical impurities in ice formed from very dilute solutions was observed autoradiographically, using radioactive 22NaCl or H36Cl as β-ray tracers. When water containing such radioactive solutes was frozen, the segregation of solute occurred primarily along grain boundaries and partly in grains. Successive autoradiography enabled us to observe the heterogeneous distributions of segregated impurities in ice.


2015 ◽  
Vol 60 (3) ◽  
pp. 2403-2407 ◽  
Author(s):  
W. Wołczyński

Abstract Solute segregation/redistribution model for some eutectic alloys is presented. The differential equation for the solute micro-segregation during solidification accompanied by the back-diffusion is formulated. The solution to this equation results in the definitions of: solidification path, solid/liquid (s/l) interface path and redistribution path. An equation for the estimation of the amount of equilibrium and non-equilibrium precipitates is also delivered. It is proved that the current model is universal one. Thus, the model reduces perfectly, mathematically to both description of diffusion-less solidification and model of equilibrium solidification.


2010 ◽  
Vol 1267 ◽  
Author(s):  
Juan Zhou ◽  
Qing Jie ◽  
Qiang Li

AbstractWe have prepared a variety of filled skutterudites through non-equilibrium synthesis by converting melt-spun ribbons into single phase polycrystalline bulk under pressure. In general, better thermoelectric properties are found in these samples. In this work, we performed microstructure characterization of non-equilibrium synthesized p-type filled skutterudite CeFe4Sb12 by X-ray diffraction, scanning electron microscopy and transmission electron microscopy in order to understand the structural origin of the improved thermoelectric properties. It is found that the non-equilibrium synthesized samples have smaller grain size and cleaner grain boundaries when compared to the samples prepared by the conventional solid-state reaction plus long term annealing. While smaller grain size can help reduce the lattice thermal conductivity, cleaner grain boundaries ensure higher carrier mobility and subsequently, higher electrical conductivity at the application temperatures.


Sign in / Sign up

Export Citation Format

Share Document