| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing: Length-Scale Phenomena in Mechanical Response
|
| Presentation Title |
Enhanced High-Temperature Performance of LPBF-Produced Inconel 718 Alloy through δ-phase control |
| Author(s) |
Hyokyung Sung, Sangyeol Ha, Won-Seok Ko, Jae Bok Seol |
| On-Site Speaker (Planned) |
Hyokyung Sung |
| Abstract Scope |
The highest-strength Inconel 718 alloy used in aviation and, increasingly in jet turbine engine (to 650 °C) requires a high-temperature stable solid-state co-precipitation. Here, we overturned the concept of the δ-phase strengthening in LPBF-produced Inconel 718 alloy, in which a high number of LPBF-produced δ-phase achieve the highest combination of strength (~1.2 GPa) and ductility (~23%) at 650 °C. The δ-phases formed at Inconel grain interior showed temperature-dependent strengthening mechanisms: shearing events with dislocation slip and the resultant consequence of shearing plane steps upon mechanical loading at room temperature, while bending (without the formation of steps) by dislocations upon high-temperature loading at 650 °C. Interestingly, upon loading at 650 °C the gliding dislocations were accommodated at γ''/δ interfaces and bended the δ-phase, and thereby, leading to a local disordering transition of δ-phase. Therefore, a low yield strength and strain hardening rate was obtained during tensile deformation at 650 °C. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Additive Manufacturing, High-Temperature Materials, Mechanical Properties |