Adsorption, surface energy and the driving force for the migration of grain boundaries in substitutional alloys

✍ Scribed by G.J. Cosgrove; A.H. King

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 450 KB
• Volume: 123
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/0921-5093(90)90207-j

✦ Synopsis

A thermodynamic model for the solute flux driven migration of grain boundaries in substitutional alloys based upon adsorption has been developed. The model envisions the grain boundary core as a distinct phase separating interfaces of different atomic structure on either side. Equations for the composition and surface energy oj adsorbed layers have been derived in terms of the local grain boundary core concentration. As the free energy curves for layers of different composition result in different equilibria within the core, a gradient in chemical potential exists across the grain boundary. It is shown that this free energy gradient can drive migration of the grain boundary in the opposite direction at a rate proportional to the difference between the core chemical potentials.