Grain-boundary segregation and dynamic solute drag theory—A phase-field approach

2007 ◽  
Vol 55 (3) ◽  
pp. 955-960 ◽  
Author(s):  
Klara Grönhagen ◽  
John Ågren
2006 ◽  
Vol 981 ◽  
Author(s):  
Zheng Lu ◽  
Roy G Faulkner

AbstractThe understanding of radiation-induced grain boundary segregation (RIS) has considerably improved over the past decade. New models have been introduced and much effort has been devoted to obtaining comprehensive information on segregation from the literature. Analytical techniques have also improved so that chemical analysis of layers 1 nm thick is almost routine. This invited paper will review the major methods used currently for RIS prediction: namely, Rate Theory, Inverse Kirkendall, and Solute Drag approaches. A summary is made of the available data on phosphorus RIS in reactor pressure vessel (RPV) steels. This will be discussed in the light of the predictions of the various models in an effort to show which models are the most reliable and easy to use for forecasting P segregation behaviour in steels. A consequence of RIS in RPV steels is a radiation induced shift in the ductile to brittle transition temperature (DBTT). It will be shown how it is possible to relate radiation-induced P segregation levels to DBTT shift. Examples of this exercise will be given for RPV steels and for ferritic steels being considered for first wall fusion applications. Cr RIS in high alloy stainless steels and associated irradiation-assisted stress corrosion cracking (IASCC) will be briefly discussed.


Nanoscale ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 3552-3563
Author(s):  
Christopher M. Barr ◽  
Stephen M. Foiles ◽  
Malek Alkayyali ◽  
Yasir Mahmood ◽  
Patrick M. Price ◽  
...  

In nanocrystalline alloys, the anisotropy in grain boundary segregation and its impact on dynamic solute drag plays a key role in the thermal stability of these systems during processing treatments or under service conditions.


2020 ◽  
Vol 22 (5) ◽  
pp. 3030-3036 ◽  
Author(s):  
Kun Shen ◽  
Yixuan Wang ◽  
Jun Zhang ◽  
Yi Zong ◽  
Gengwei Li ◽  
...  

Phase field calculated effective diffusivity Deff of Li vacancy in anti-perovskite Li3OCl is shown as a function of average grain sizes. Li vacancy segregation reinforces the negative contribution of grain boundaries on the overall Li diffusion.


Author(s):  
C.L. Briant

Grain boundary segregation is the process by which solute elements in a material diffuse to the grain boundaries, become trapped there, and increase their local concentration at the boundary over that in the bulk. As a result of this process this local concentration of the segregant at the grain boundary can be many orders of magnitude greater than the bulk concentration of the segregant. The importance of this problem lies in the fact that grain boundary segregation can affect many material properties such as fracture, corrosion, and grain growth.One of the best ways to study grain boundary segregation is with Auger electron spectroscopy. This spectroscopy is an extremely surface sensitive technique. When it is used to study grain boundary segregation the sample must first be fractured intergranularly in the high vacuum spectrometer. This fracture surface is then the one that is analyzed. The development of scanning Auger spectrometers have allowed researchers to first image the fracture surface that is created and then to perform analyses on individual grain boundaries.


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