TY - JOUR
T1 - Phase-field modeling of θ′ precipitation kinetics in 319 aluminum alloys
AU - Ji, Yanzhou
AU - Ghaffari, Bita
AU - Li, Mei
AU - Chen, Long Qing
N1 - Funding Information:
The authors are grateful to Drs. Shannon Weakley-Bollin, Ruijie Zhang and John Allison for providing the TEM data and for useful discussions. The authors acknowledge the financial support from the University Research Program of Ford Motor Company .
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/8
Y1 - 2018/8
N2 - Understanding the morphological evolution of precipitates is critical for evaluating their hardening effects and therefore improving the yield strength of an alloy during aging. Here we present a three-dimensional phase-field model for capturing both the nucleation and the growth kinetics of the precipitates and apply it to modeling θ′ precipitates in 319 aluminum alloys. The model incorporates the relevant thermodynamic data, diffusion coefficients, and the anisotropic misfit strain from literature, together with the anisotropic interfacial energy from first-principles calculations. The modified classical nucleation theory is implemented to capture the nucleation kinetics. The model parameters are optimized by comparing the simulation results to the experimentally measured peak number density, average diameters, average thicknesses and volume fractions of precipitates during isothermal aging at 463 K (190 °C), 503 K (230 °C) and 533 K (260 °C). Further model improvements in terms of prediction accuracy of the precipitate kinetics in 319 alloys and the remaining challenges are discussed.
AB - Understanding the morphological evolution of precipitates is critical for evaluating their hardening effects and therefore improving the yield strength of an alloy during aging. Here we present a three-dimensional phase-field model for capturing both the nucleation and the growth kinetics of the precipitates and apply it to modeling θ′ precipitates in 319 aluminum alloys. The model incorporates the relevant thermodynamic data, diffusion coefficients, and the anisotropic misfit strain from literature, together with the anisotropic interfacial energy from first-principles calculations. The modified classical nucleation theory is implemented to capture the nucleation kinetics. The model parameters are optimized by comparing the simulation results to the experimentally measured peak number density, average diameters, average thicknesses and volume fractions of precipitates during isothermal aging at 463 K (190 °C), 503 K (230 °C) and 533 K (260 °C). Further model improvements in terms of prediction accuracy of the precipitate kinetics in 319 alloys and the remaining challenges are discussed.
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U2 - 10.1016/j.commatsci.2018.04.051
DO - 10.1016/j.commatsci.2018.04.051
M3 - Article
AN - SCOPUS:85046747995
VL - 151
SP - 84
EP - 94
JO - Computational Materials Science
JF - Computational Materials Science
SN - 0927-0256
ER -