| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Spatially Tailored Materials: Processing-Structure-Properties
|
| Presentation Title |
Multiscale characterization of an additively manufactured property graded Ni-base alloy
for molten-salts\supercritical-CO2 heat exchangers |
| Author(s) |
Qing-Qiang Ren, Yi-Feng Su, Thomas Feldhausen, Rebecca A. Kurfess, Kenton Blane Fillingim, Soumya Nag, Rishi R. Pillai |
| On-Site Speaker (Planned) |
Qing-Qiang Ren |
| Abstract Scope |
In this work, we demonstrate the feasibility of directed energy deposition (DED) to manufacture a dual-corrosion resistant Ni-based alloy (Hastelloy N and Haynes 282), that meets the high temperature operation requirements of a molten-salts\supercritical-CO2 (sCO2) heat exchanger. A combination of multiscale characterization techniques and computational thermodynamics was employed to evaluate the cracking susceptibilities during fabrication and predict the microstructural stability of the material. Very good agreement was achieved between the observed and predicted phases and phase fractions of the as-printed material. A careful characterization of the transition zone between the two terminal alloy chemistries revealed potential precipitation strengthening (γ') on the Hastelloy N side while columnar-shaped M23C6 and γ' precipitates that formed at grain boundaries (GBs) of the transition zone that likely minimized the local interfacial energies. Both these mechanisms are believed to increase the interfacial stability but their performance in high temperatures requires further investigation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Characterization, Computational Materials Science & Engineering |