About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
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Additive Manufacturing Modeling, Simulation, and Machine Learning: Microstructure, Mechanics, and Process
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Presentation Title |
Tailoring Formation of TCP Phases during Additively Manufactured Inconel 625 by CALPHAD-based Simulations with Experimental Validations |
Author(s) |
Hui Sun, Shun-Li Shang, Shipin Qin, Allison Beese, Zi-Kui Liu |
On-Site Speaker (Planned) |
Hui Sun |
Abstract Scope |
Detrimental topologically close-packed (TCP) phases are frequently observed in additive manufacturing (AM) due to elemental segregation and fast-cooling rate. Here, we investigate the formation of the TCP phase δ in Inconel-625 fabricated using laser powder bed fusion AM through an integrated computational and experimental approach. The unwanted δ phase grows much faster in the samples subjected to stress-relief heat treatments than those in wrought samples due to fast-cooling rates during AM, resulting in segregations of Nb and Mo. CALPHAD-based thermodynamic modeling was performed aided by first-principles calculations based on density functional theory, which provides energetics for proper modeling of δ. The new database is used to design the chemistry within the alloy specification tolerance and identify suitable processes of heat treatment to decrease the formation of δ phase. It is shown that the combination of finite element predictions and kinetic simulations enables the modification of elemental segregation by adjusting AM processing parameters. |