Flux-driven nucleation at interfaces during reactive diffusion

International audienceNucleation of intermetallic compounds and of voids at interfaces during reactive diffusion is treated with account of influence of the flux divergence in the nucleation regions of the real space as an additional term for drift in the size space (in Fokker-Planck equation for nucleation). Such approach enables the construction of effective Gibbs nucleation barrier which may (in the broad region of parameters) increase to infinity meaning the full suppression of nucleation, or, by the contrast, decrease assisting the nucleation. The introduced effective nucleation barriers depend on kinetic factors - on the ratio of diffusivities in nucleating and in neighboring phases. Thus, the competition of stable and metastable phases is reconsidered, as well as nucleation of Kirkendall/Frenkel voids at the interfaces

Phase growth competition in solid/liquid reactions between copper or Cu3Sn compound and liquid tin-based solder

International audienceInterfacial reaction between solid e-Cu3Sn compound and liquid Sn at 250 °C is studied for the first time. The reaction product formed at the e-Cu3Sn/liquid Sn interface consists of the single g-Cu6Sn5 phase. The growth kinetics of the g phase formed at the incremental e/liquid Sn couple (e/g/Sn configuration) is compared to that of g phase formed at the classical Cu/liquid Sn couple (Cu/e/g/Sn configuration). The experimental method con- sists first in processing of intimate interfaces by dipping peaces of solid e-Cu3Sn compound and Cu in liquid Sn for 1 s at 250 °C. Afterwards, isothermal holding of such pre- performed couples for 10, 30, 120 and 480 min at 250 °C are performed for both couples. A theoretical analysis of the growth kinetics of g phase and comparison of its in both configurations are performed

The effect of introducing stochasticity to kinetic mean-field calculations: Comparison with lattice kinetic Monte Carlo in case of regular solid solutions

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