Keywords :
AlSi10Mg; CALPHAD; KKS; LPBF; Phase-field modeling; Calculation of PHAse diagram; Kim–kim–suzuki; Laser powder bed fusion; Laser powders; matrix; Microstructure evolutions; Non-isothermal process; Phase field models; Phase fields; Powder bed; Computer Science (all); Chemistry (all); Materials Science (all); Mechanics of Materials; Physics and Astronomy (all); Computational Mathematics; Physics - Materials Science
Abstract :
[en] The out-of-equilibrium heterogeneous microstructure typical of AlSi10Mg processed by Laser Powder Bed Fusion (LPBF) is often modified by further heat treatment to improve its ductility. According to literature, extensive experimental investigations are generally required in order to optimize these heat treatments. In the present work, a phase-field approach is developed based on an extended Kim–Kim–Suzuki (KKS) model to guide and accelerate the post-treatment optimization. Combined with CALculation of PHAse Diagrams (CALPHAD) data, this extended KKS model predicts microstructural changes under anisothermal conditions. To ensure a more physical approach, it takes into account the enhanced diffusion by quenched-in excess vacancies as well as the elastic energy due to matrix/precipitate lattice mismatch. As the developed model includes the computation of the evolution of the thermo-physical properties, its results are validated through comparison with experimental DSC curves measured during the non-isothermal loading of as-built LPBF AlSi10Mg. The computed microstructure evolution reproduces the microstructural observation and successfully explains the peaks in the DSC heat flow curve. It thus elucidates the detailed microstructural evolution inside the eutectic silicon phase by considering the growth and coalescence of silicon precipitates and the matrix desaturation.
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique
FEDER - Fonds Européen de Développement Régional
SPW EER - Service Public de Wallonie. Economie, Emploi, Recherche
Funding text :
As Research Director of F.R.S-FNRS, A.M. Habraken acknowledges the support of this institution. CAREM of the University of Liege is acknowledged for providing SEM/EDS facilities. The ULi\u00E8ge research council of Sciences and Techniques and Engineering research council are acknowledged for the post-doc IN IPD-STEMA 2019 grant and faculty post doc grant 2021 of Seifallah Fetni. The authors wish to acknowledge the financial support of the European Regional Development Fund and the Walloon Region under convention FEDER, Spain \u201CIawatha\u201D and of the Walinnov Longlife AM project, convention n\u00B01810016, funded by the Service Public de Wallonie - Economie Emploi Recherche (SPW-EER). The authors are also grateful to Mr O. Rigo (Sirris) and Dr S. Michotte (AnyShape), for their help with the fabrication of the samples.The authors wish to acknowledge the financial support of the European Fund for Regional Development and the Walloon Region under convention FEDER \u201CIawatha\u201D and of the Walinnov Longlife AM project, convention n\u00B01810016, funded by the Service Public de Wallonie - Economie Emploi Recherche (SPW-EER) . The authors are also grateful to Mr O. Rigo (Sirris) and Dr S. Michotte (AnyShape), for their help with the fabrication of the samples.
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