About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing and Innovative Feedstock Processing for Multifunctional Materials
|
| Presentation Title |
Defect Formation and Microstructural Evolution in Powder-Fed Directed Energy Deposition of Al6061 |
| Author(s) |
Nima Kalantari, Chang-Hwan Choi |
| On-Site Speaker (Planned) |
Nima Kalantari |
| Abstract Scope |
Laser powder directed energy deposition enables fabrication and repair of aluminum components, but Al6061 remains difficult to process because of cracking, porosity, and melt-pool instability. This study investigates the influence of energy density on defect formation and microstructural evolution during multilayer directed energy deposition of Al6061. Laser power and scanning speed were varied using a statistically designed experimental framework. Crack networks were quantified using cumulative crack density, an image-based metric that includes open cracks and partially healed crack paths, while porosity was evaluated from metallographic cross sections. Microstructural analysis shows that cracking is associated with reheated partially melted zones, solute-enriched interdendritic regions, and melt-pool boundaries, indicating combined liquation and solidification cracking. Porosity remained low during stable conduction-mode melting but increased sharply after keyhole-related instability. The resulting defect–microstructure–processing relationship establishes a reduced-defect processing window and provides a foundation for future localized composition and thermal-history control strategies. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Aluminum, Characterization, Solidification |