Role of segregation in diffusion-induced grain boundary migration

A. Brokman*, A. H. King, A. J. Vilenkin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

The problem of grain boundary motion in the diffusion field of a solute is formulated for the case of infinitely fast diffusion along a straight boundary. The steady state solution suggests that (de)alloying occurs by two different modes, namely: the solute diffusion through the stationary boundary to the bulk, or by diffusion-induced grain boundary migration (DIGM). The transition from one mode to another depends on the grain boundary segregation coefficient. The result enables an assessment of the relative importance of different possible driving forces. When the equilibrium concentrations of the bulk solute with the external gas is low, the entropy of mixing is the leading driving force. DIGM does not occur in isotope solution because the solute atom does not segregate to the boundary. Based on this theory, we construct the phase diagram in the plane of the (gas/bulk) equilibrium concentration vs the segregation coefficient, representing the transition from DIGM to alloying via stationary boundaries.

Original languageEnglish
Pages (from-to)1-11
Number of pages11
JournalActa Materialia
Volume49
Issue number1
DOIs
StatePublished - 8 Jan 2001

Fingerprint

Dive into the research topics of 'Role of segregation in diffusion-induced grain boundary migration'. Together they form a unique fingerprint.

Cite this