ISSN:
1573-2746
Schlagwort(e):
grain boundaries
;
twist and tilt boundaries
;
solute-atom segregation
;
Metropolis Monte Carlo
;
simulation
;
nickel-platinum alloys
;
Langmuir-McLean
;
Fowler-Guggenheim segregation models
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
Abstract Using the Metropolis algorithm Monte Carlo technique solute-atom segregation is studied at two vicinal grain boundaries (GBs)—the Σ = 5/(002)/θ = 36.89° symmetrical twist and the Σ = 5/(310)/θ = 53.13° symmetrical tilt—at 850 K on the Ni-rich side of the Ni-Pt phase diagram, over the concentration range 0–10 at.% Pt. Unlike the Pt-rich side of the phase diagram the structures of both GBs remain stable in this concentration range. The dilute limit behavior for most GB sites extends to at least 0.1 at. %. At higher concentrations the effective segregation energies steadily decrease with increasing solute concentrations, due to solute-solute interactions between segregated atoms, until saturation occurs. It is argued that simple statistical mechanical models, e.g., the Fowler-Guggenheim model do not work well, even in the case of simple vicinal GBs.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1008697503079
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