Simultaneous segregation at coherent and semicoherent heterophase interfaces.
By employing a combination of three-dimensional atom-probe tomography and first-principles calculations, significant qualitative and quantitative differences in solute segregation at coherent and semicoherent interfaces bounding a single θ^{'} precipitate in an Al-Cu-based alloy are found. Qualitatively, localized segregation is observed at the semicoherent interface, whereas delocalized behavior is present at the coherent facets. Quantitatively, segregation at the semicoherent interface is a factor of 2 greater than at the coherent interface, resulting in a decrease in interfacial energy that is more than 5 times greater than that observed at the coherent facet. These observations illustrate unambiguously the strong couplings among interface structure, chemical composition, and energetics.
Biswas
Aniruddha
A
Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, USA.
Siegel
Donald J
DJ
Seidman
David N
DN