A 3D analysis of dendritic solidification and mosaicity in Ni-based single crystal superalloys
- Ni-based single crystal superalloys contain microstructural regions that are separated by low-angle grain boundaries. This gives rise to the phenomenon of mosaicity. In the literature, this type of defect has been associated with the deformation of dendrites during Bridgman solidification. The present study introduces a novel serial sectioning method that allows to rationalize mosaicity on the basis of spatial dendrite growth. Optical wide-field micrographs were taken from a series of cross sections and evaluated using quantitative image analysis. This allowed to explore the growth directions of close to 2500 dendrites in a large specimen volume of approximately 450 \(mm^{3}\). The application of tomography in combination with the rotation vector base-line electron back-scatter diffraction method allowed to analyze how small angular differences evolve in the early stages of solidification. It was found that the microstructure consists of dendrites with individual growth directions that deviate up to \(\approx\)4° from the average growth direction of all dendrites. Generally, individual dendrite growth directions coincide with crystallographic <001> directions. The quantitative evaluation of the rich data sets obtained with the present method aims at contributing to a better understanding of elementary processes that govern competitive dendrite growth and crystal mosaicity.
Author: | Felicitas ScholzGND, Mustafa CevikGND, Philipp HallenslebenGND, Pascal ThomeORCiDGND, Gunther EggelerORCiDGND, Jan FrenzelORCiDGND |
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URN: | urn:nbn:de:hbz:294-85324 |
DOI: | https://doi.org/10.3390/ma14174904 |
Parent Title (English): | Materials |
Publisher: | MDPI |
Place of publication: | Basel |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2022/01/14 |
Date of first Publication: | 2021/08/28 |
Publishing Institution: | Ruhr-Universität Bochum, Universitätsbibliothek |
Tag: | competitive dendrite growth; mosaicity; quantitative tomographic characterization; seeded Bridgman solidification; single crystal superalloys |
Volume: | 14 |
Issue: | 17, Article 4904 |
First Page: | 4904-1 |
Last Page: | 4904-24 |
Institutes/Facilities: | Institut für Werkstoffe |
Dewey Decimal Classification: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften, Maschinenbau |
open_access (DINI-Set): | open_access |
faculties: | Fakultät für Maschinenbau |
Licence (English): | Creative Commons - CC BY 4.0 - Attribution 4.0 International |