| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Materials Design and Alloy Development VI – Closed-Loop Alloy Design
|
| Presentation Title |
Microcrack Mechanisms during Additive Manufacturing of γ /γ' Ni-base Superalloy and Alloy Design to Eliminate Cracking |
| Author(s) |
Nathaniel Badgett, John O'Connell, Bhaskar Majumdar, Kevin Garber, Mohammad Chowdhury, Timothy Nice |
| On-Site Speaker (Planned) |
Nathaniel Badgett |
| Abstract Scope |
High temperature γ /γ' Ni-base superalloys with high γ' content (>60 vol%) have been difficult to fabricate microcrack-free using additive manufacturing (AM). Here, we focused on the high γ' base CM247LC alloy. Experiments show significant microcracking along high-angle grain boundaries during AM. In order to better understand the mechanisms leading to cracking, SEM/EDS and TEM/EELS techniques were used to investigate the final solidifying phases and carbon-rich zones along crack paths. These results along with CALPHAD were used to develop alloys to mitigate cracking. The observations were conducted using laser line scans of arc-melted buttons with specific compositions; observed elemental segregation was compared with the Scheil model. Both carbides and Hf-rich zones were observed along crack paths; however, the elimination of Hf did not lead to a crack-free alloy. Based on these mechanisms and our design approach we will demonstrate a modified composition of CM247LC that completely eliminates cracking during AM. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, Other, Other |