Precipitate dissolution during deformation induced twin thickening in a CoNi-base superalloy subject to creep
File(s)
Published version
Author(s)
Vorontsov, Vassili A
McAuliffe, Thomas P
Hardy, Mark C
Dye, David
Bantounas, Ioannis
Type
Journal Article
Abstract
The tensile creep performance of a polycrystalline Co/Ni-base superalloy with a multimodal γ distribution has been examined at 800◦C and 300 MPa. The rupture life of the alloy is comparable to that of
RR1000 tested under similar conditions. Microstructural examination of the alloy after testing revealed
the presence of continuous γ precipitates and M23C6 carbides along the grain boundaries. Intragranularly, coarsening of the secondary γ precipitates occurred at the expense of the fine tertiary γ
. Long
planar deformation bands, free of γ
, were also observed to traverse individual grains. Examination of
the deformation bands confirmed that they were microtwins. Long sections of the microtwins examined
were depleted of γ stabilising elements across their entire width, suggesting that certain alloy compositions are susceptible to precipitate dissolution during twin thickening. A mechanism for the dissolution
of the precipitates is suggested based on the Kolbe reordering mechanism.
RR1000 tested under similar conditions. Microstructural examination of the alloy after testing revealed
the presence of continuous γ precipitates and M23C6 carbides along the grain boundaries. Intragranularly, coarsening of the secondary γ precipitates occurred at the expense of the fine tertiary γ
. Long
planar deformation bands, free of γ
, were also observed to traverse individual grains. Examination of
the deformation bands confirmed that they were microtwins. Long sections of the microtwins examined
were depleted of γ stabilising elements across their entire width, suggesting that certain alloy compositions are susceptible to precipitate dissolution during twin thickening. A mechanism for the dissolution
of the precipitates is suggested based on the Kolbe reordering mechanism.
Date Issued
2022-06-15
Date Acceptance
2022-04-11
Citation
Acta Materialia, 2022, 232, pp.1-11
ISSN
1359-6454
Publisher
Elsevier
Start Page
1
End Page
11
Journal / Book Title
Acta Materialia
Volume
232
Copyright Statement
© 2022 The Author(s). Published by Elsevier Ltd on behalf of Acta Materialia Inc.
This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
License URL
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000830498400008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Technology
Materials Science, Multidisciplinary
Metallurgy & Metallurgical Engineering
Materials Science
Cobalt-base superalloys
Creep
Microtwinning
Atomic ordering
Transmission electron microscopy
NI-BASED SUPERALLOYS
LOW-CYCLE FATIGUE
INTERMEDIATE TEMPERATURES
CARBIDE PRECIPITATION
MATRIX DISLOCATIONS
SINGLE-CRYSTALS
STACKING-FAULTS
SEGREGATION
MECHANISM
PHASE
Publication Status
Published
Article Number
ARTN 117936
Date Publish Online
2022-04-23