A multi-phase field study of the role of grain boundary diffusion in growth of Cu6Sn5 intermetallic compound during early stage of soldering reaction

2013 ◽  
Author(s):  
Chang-Bo Ke ◽  
Min-Bo Zhou ◽  
Xin-Ping Zhang
Keyword(s):  
Intermetallic Compound ◽  
Grain Boundary ◽  
Field Study ◽  
Phase Field ◽  
Boundary Diffusion ◽  
Early Stage ◽  
Grain Boundary Diffusion ◽  
Soldering Reaction ◽  
Multi Phase

The role of solute segregation in grain boundary diffusion

1982 ◽  
Vol 379 (1776) ◽  
pp. 159-178 ◽  
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Boundary Energy ◽  
Grain Boundary Diffusion ◽  
Enrichment Ratio ◽  
Tin Alloys ◽  
Bulk Diffusivity ◽  
Tin Content ◽  
Grain Boundary Transport

In measurements of grain boundary transport it is the product of the grain boundary enrichment ratio and the grain boundary diffusivity that is usually obtained. This work presents the first study in which these two terms are separated and in which the role of the grain boundary composi­tion in grain boundary diffusion is analysed in detail. This leads to the general prediction that the grain boundary diffusion of solute and solvent will be reduced by strongly segregating solutes if they do not simultaneously enhance the bulk diffusivities. The converse occurs if the solute weakly segregates but strongly enhances the bulk diffusivities. The diffusion measurements are made in iron–tin alloys in the tempera­ture range 563–750 °C by using radiotracers, and the segregation measure­ments, similarly, by Auger electron spectroscopy. The measured bulk diffusivities are similar to those found previously. The grain boundary diffusivities, determined via Suzuoka’s (1964) analysis, for iron and tin in pure iron have pre-exponential coefficients of 225 x 10 -4 and 9.2 x 10 -4 m 2 s -1 and activation energies of 165770 and 166600 J mol -1 respectively. Contrary to the increase in the bulk diffusivity produced by the ‘fast’ diffuser, tin, both grain boundary diffusivities are sharply reduced as the tin content rises. These and earlier results are interpreted through the effect of tin segregation on the grain boundary energy described by the theory of Borisov et al . (1964).

Role of segregating impurities in grain-boundary diffusion

2007 ◽  
Vol 126 (9) ◽  
pp. 094707 ◽  
Author(s):  
P. Kansuwan ◽  
J. M. Rickman
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion

scholarly journals Role of grain boundary diffusion in H-D exchange in mantle xenoliths

2020 ◽  
Author(s):  
Konstantinos Thomaidis ◽  
Jannick Ingrin
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Hydrogen Exchange ◽  
Boundary Diffusion ◽  
Water Concentration ◽  
Grain Boundary Diffusion ◽  
Mantle Xenoliths ◽  
Host Magma ◽  
Oxidation Reduction

<p>Water concentration in pyroxenes from mantle xenoliths is frequently used to trace water content in the lithospheric mantle. We do not understand yet how these pyroxenes can preserve a memory of their deep equilibrium during their transport to the surface. In an attempt to evaluate the role of grain boundaries in the exchange of hydrogen between the pyroxenes of the xenoliths and the host magma, we have launched a program of experiments of H exchange in blocks of mantle xenoliths of centimetre size. The blocks, all from the same xenolith, contain clinopyroxenes, orthopyroxenes and olivine of mm to sub-millimetre size. We present here the results of a series of H-D exchange performed at 600, 700 and 900 <sup>o</sup>C at room pressure in a deuterium enriched gas. OH-OD profiles recorded by micro-infrared spectroscopy in pyroxenes at the edge of the block are only slightly different from the ones recorded in pyroxenes at the centre of the block. These results show that the diffusion/solubility of hydrogen in grain boundaries is fast enough to equilibrate rapidly the grains at the center of the xenoliths. It proves that in nature the δD signature of xenoliths is very likely controlled by the equilibrium with the host magma even in the case of xenoliths with large grain size.</p><p>We will also present preliminary results on the role of grain boundary diffusion in the control of hydrogen exchange involving reactions activated at a higher temperature such as the oxidation-reduction of iron (1/2H<sub>2</sub> + Fe<sup>3+</sup>  =  H<sub>i</sub><sup>+</sup> + Fe<sup>2+</sup>) and the formation/destruction of cation vacancies.</p>

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