On the increase of the precipitated volume fraction during Ostwald ripening, exemplified for aluminium–lithium alloys

Kalogeridis, Avraam; Pešička, Josef; Nembach, E.

doi:10.1016/s0921-5093(99)00083-0

Cited by 10 publications

(3 citation statements)

References 18 publications

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“…Though the simulation results (in the absence of coupling) are consistent with the conventional theories of ripening, it is evident that these theories cannot simultaneously explain the experimental observations in terms of average radius and size distribution of the precipitates. This finding is also in agreement with the previous studies 8,10,13 , reviewed in the introduction section, which found disagreements between the experimentally observed size distributions and classical ripening theories. In the presence of the chemo-mechanical coupling (and the Li sink), instead, the size distribution remains finite and the precipitates shrink (dissolve) together and lose their Li content only to the sink, as the conventional ripening is inactive due to the inverse ripening.…”

Section: Resultssupporting

confidence: 93%

“…The comparison between the model and experimental results suggests a drastic increase in the capillarity length with the precipitate volume fraction, i.e. with the nominal alloy composition 8 . This is, however, in contrast to the fact that the equilibrium compositions of the coexisting phases (the precipitate and matrix phase) are rather thermodynamic functions independent of the nominal composition of the alloy.…”

Section: Introductionmentioning

confidence: 82%

“…Despite the fact that an overwhelming number of investigations reporting the classical ripening scaling with n = 3 are in agreement with the LSW theory 5,6 , their finding regarding the size distribution of δ ′ precipitates are controversial. This motivated a detailed study of precipitation with different alloy compositions, that is, different precipitate fractions, in the late 1990s by Nembach and co-workers 8 . They analyzed the size distribution based on a model proposed by Ardell 9 , which consider the effect of precipitate volume fraction on the size distribution in the later stages of ripening under purely diffusive conditions.…”

Section: Introductionmentioning

confidence: 99%

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First Evidence for Mechanism of Inverse Ripening from In-situ TEM and Phase-Field Study of δ′ Precipitation in an Al-Li Alloy

Park

Kamachali

Kim

et al. 2019

Sci Rep

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In-situ TEM investigation of aging response in an Al–7.8 at.% Li was performed at 200 °C up to 13 hours. Semi-spherical δ ′ precipitates growing up to an average radius of 7.5 nm were observed. The size and number of individual precipitates were recorded over time and compared to large-scale phase-field simulations without and with a chemo-mechanical coupling effect, that is, concentration dependence of the elastic constants of the matrix solid solution phase. This type of coupling was recently reported in theoretical studies leading to an inverse ripening process where smaller precipitates grew at the expense of larger ones. Considering this chemo-mechanical coupling effect, the temporal evolution of number density, average radius, and size distribution of the precipitates observed in the in-situ experiment were explained. The results indicate that the mechanism of inverse ripening can be active in this case. Formation of dislocations and precipitate-free zones are discussed as possible disturbances to the chemo-mechanical coupling effect and consequent inverse ripening process.

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Section: Resultssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 82%