| About this Abstract |
| Meeting |
TMS Specialty Congress 2025
|
| Symposium
|
The 7th International Congress on 3D Materials Science (3DMS 2025)
|
| Presentation Title |
Three-Dimensional Characterization of Dislocation Networks and Orientation Gradients in LPBF CoNi-Based Superalloys |
| Author(s) |
James Lamb, Evan Raeker, Nicolò Maria della Ventura, McLean Echlin, Tresa Pollock |
| On-Site Speaker (Planned) |
James Lamb |
| Abstract Scope |
Laser powder bed fusion (LPBF) creates complex thermomechanical conditions that introduce significant residual stresses in printed parts. As a result, dense cellular dislocation networks and severe orientation gradients develop in the as-printed material, often leading to increased strength and work hardening when compared to traditionally manufactured components. Grain-scale and cell-scale misorientations are characterized in 3D using TriBeam tomography on LPBF prints of a CoNi-based superalloy. The resulting EBSD data enables calculation of geometrically necessary dislocation (GND) densities and grain-based misorientation metrics. Dislocation cells are observed to transition between orthogonal growth directions across melt pool boundaries. Concurrently, significant intracellular orientation gradients develop along the growth axis of solidification cells and between neighboring cells. Cell-scale misorientations accumulate along the build direction, creating larger orientation gradients, upwards of 50° over 500 µm, at the grain scale. These findings reveal fundamental relationships between processing conditions, microstructural evolution, and residual stress development during LPBF. |
| Proceedings Inclusion? |
Undecided |