Local x-ray diffraction analysis of the structure of dendrites in single-crystal nickel-base superalloys
- Bundesanstalt fuer Materialforschung und Pruefung, Berlin (Germany)
- Russian Inst. of Aviation Materials, Moscow (Russian Federation)
- Technische Univ. Berlin (Germany)
The structure of the dendrites in the single-crystal nickel-base superalloys SC16, SRR99 and CMSX4 with different refractory element levels (Mo + Ta + W + Re) has been investigated by local X-ray diffraction. A special technique was used to improve the spatial resolution of the X-ray diffraction and to enable the precise control of the X-ray spot position within the dendritic structure. A significant change of the {gamma}/{gamma}{prime}-lattice misfit was found within the dendrite in the superalloys with higher refractory element levels SRR99 and CMSX4. The observed misfit change is based on the change of the {gamma}-lattice parameter due to segregation of W and Re. The intensity of the X-ray beam reflected from the dendrite periphery was found to be weaker than that from the dendrite centre because of the mosaicity. Therefore misfit measurements without knowledge of the X-ray spot position in the dendritic structure lead to values that correspond more to the dendrite core.
- OSTI ID:
- 599727
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 12 Vol. 45; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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