Stability of TaC precipitates in a Co-Re-based alloy being developed for ultra-high-temperature applications
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F16%3A00463723" target="_blank" >RIV/61389005:_____/16:00463723 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1107/S1600576716009006" target="_blank" >http://dx.doi.org/10.1107/S1600576716009006</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1107/S1600576716009006" target="_blank" >10.1107/S1600576716009006</a>
Alternative languages
Result language
angličtina
Original language name
Stability of TaC precipitates in a Co-Re-based alloy being developed for ultra-high-temperature applications
Original language description
Co-Re alloys are being developed for ultra-high-temperature applications to supplement Ni-based superalloys in future gas turbines. The main goal of the alloy development is to increase the maximum service temperature of the alloy beyond 1473 K, i.e. at least 100 K more than the present single-crystal Ni-based superalloy turbine blades. Co-Re alloys are strengthened by carbide phases, particularly the monocarbide of Ta. The binary TaC phase is stable at very high temperatures, much greater than the melting temperature of superalloys and Co-Re alloys. However, its stability within the Co-Re-Cr system has never been studied systematically. In this study an alloy with the composition Co-17Re-23Cr-1.2Ta-2.6C was investigated using complementary methods of small-angle neutron scattering (SANS), scanning electron microscopy, X-ray diffraction and neutron diffraction. Samples heat treated externally and samples heated in situ during diffraction experiments exhibited stable TaC precipitates at temperatures up to 1573 K. The size and volume fraction of fine TaC precipitates (up to 100 nm) were characterized at high temperatures with in situ SANS measurements. Moreover, SANS was used to monitor precipitate formation during cooling from high temperatures. When the alloy is heated the matrix undergoes an allotropic phase transformation from the "phase (hexagonal close-packed) to the gamma phase (face-centred cubic), and the influence on the strengthening TaC precipitates was also studied with in situ SANS. The results show that the TaC phase is stable and at these high temperatures the precipitates coarsen but still remain. This makes the TaC precipitates attractive and the Co-Re alloys a promising candidate for high-temperature application.
Czech name
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Czech description
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Classification
Type
J<sub>x</sub> - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
BM - Solid-state physics and magnetism
OECD FORD branch
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Result continuities
Project
<a href="/en/project/GB14-36566G" target="_blank" >GB14-36566G: Multidisciplinary research centre for advanced materials</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2016
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Applied Crystallography
ISSN
1600-5767
e-ISSN
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Volume of the periodical
49
Issue of the periodical within the volume
4
Country of publishing house
GB - UNITED KINGDOM
Number of pages
13
Pages from-to
1253-1265
UT code for WoS article
000382755900016
EID of the result in the Scopus database
2-s2.0-84980599266