About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Characterization of Minerals, Metals and Materials
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Presentation Title |
Effect of Single Crystal Growth Techniques on Dendritic Microstructures and Small Orientation Defects in Ni-based Superalloys |
Author(s) |
Felicitas Werner, Felicitas Scholz, Paul Git, Alexander Richter, Pascal Thome, Carolin Körner, Gunther Eggeler, Jan Frenzel |
On-Site Speaker (Planned) |
Felicitas Werner |
Abstract Scope |
We investigate how different Bridgman single crystal solidification techniques affect dendritic microstructures and low angle misorientation defects. In general, Ni-based single crystal (SX) superalloys contain low angle grain boundaries between slightly misoriented dendrites. This type of defect is referred to as crystal mosaicity. We use two approaches to prepare SX material states. First, we use the seeding method where the formation of the SX is governed by epitaxial growth from a pre-oriented seed crystal. Second, we use the helix technique, where the solid/liquid interface has to pass a narrow spiral-shaped grain selector. The different material states were characterized by advanced microscopy techniques (e.g. tomography and cross-correlation EBSD) and Laue x-ray mappings. Our results suggest that the helix technique is associated with lateral solidification growth which results in line-shaped zones with slight misorientations. In contrast, these zones have a globular character for seeded crystal growth, where no significant lateral growth occurs. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, High-Temperature Materials, |