| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Defects and Properties of Cast Metals
|
| Presentation Title |
Crystal Mosaicity in Single Crystal Ni-based Superalloys |
| Author(s) |
Jan Frenzel, Philipp Hallensleben, Felicitas Scholz, Pascal Thome, Gunther Eggeler |
| On-Site Speaker (Planned) |
Jan Frenzel |
| Abstract Scope |
We investigate the evolution of crystal mosaicity, i.e. the spread of crystal plane orientations, during seeded Bridgman processing of technical Ni-based single crystal superalloys (SXs). We combine solidification experiments performed at different solidification rates with advanced optical microscopy and quantitative image analysis. The results obtained in the present work show that crystal mosaicity is caused be dendrite deformation during solidification. Individual SXs have unique mosaicity finger prints. Most crystals differ in this respect, even when they were produced using identical processing conditions. Small differences in the orientation spread of the seed crystals and small stochastic orientation deviations continuously accumulate during solidification. Direct evidence for dendrite bending in a conventional solidification process is provided. It was observed that continuous or sudden bending events affect the growth directions of dendrites. We provide evidence which shows that some dendrites continuously bend by 1.7° over a solidification distance of 25 mm. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |