About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing of Metals: Multiscale and Non-Equilibrium Solidification Fundamentals
|
| Presentation Title |
Composition-Dependent Thermal Gradients and Microstructure Evolution in Multi-Material Laser Directed Energy Deposition of IN718–SS316 |
| Author(s) |
Tishta Das, Sourav Goswami, Shyamprasad Karagadde |
| On-Site Speaker (Planned) |
Tishta Das |
| Abstract Scope |
This work investigates how composition governs thermal behaviour and microstructure evolution in multi-material Laser Directed Energy Deposition (DED) of IN718–SS316 graded structures. A transient, composition-dependent thermal model was developed and validated using embedded thermocouples and coaxial microstructure imaging, capturing key differences between SS316-dominant and IN718-dominant layers. Simulated solidification parameters—temperature gradient (G), solidification rate (R), cooling rate (G×R), and stability ratio (G/R)—revealed that SS316-rich layers experience higher gradients and cooling rates, promoting fine cellular structures, whereas IN718-rich layers exhibit deeper melt pools, reduced gradients, and coarse columnar dendritic growth. EBSD analysis confirmed composition-driven variations in grain size, texture, and columnar-to-equiaxed transition (CET), as well as segregation-induced defects in IN718-dominant regions. By directly linking thermal fields with microstructural outcomes, this study establishes quantitative guidelines for designing robust, crack-resistant IN718–SS316 functionally graded components and highlights the critical role of composition in controlling solidification behaviour during multi-material DED. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Modeling and Simulation, Solidification |