Free Access
| Issue |
Microsc. Microanal. Microstruct.
Volume 7, Number 1, February 1996
|
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|---|---|---|
| Page(s) | 65 - 84 | |
| DOI | https://doi.org/10.1051/mmm:1996106 | |
Microsc. Microanal. Microstruct. 7, 65-84 (1996)
DOI: 10.1051/mmm:1996106
Local Order and Associated Deformation Mechanisms in the
Nicole Clement1, Armand Coujou1, Yvonne Calvayrac2, Francois Guillet2, Didier Blavette3 et Stéphane Duval3
1 CEMES-LOE/CNRS, 29 rue Jeanne Marvig, BP. 4347, 31055 Toulouse Cedex, France
2 CECM/CNRS, 15 rue Georges Urbain, 94407 Vitry Cedex, France
3 LMI, URA CNRS 808, UFR Sciences et Techniques, BP. 118, 76134 Mont Saint Aignan Cedex, France
8130B - Phase diagrams of metals and alloys.
6170J - Etch pits, decoration, transmission electron microscopy and other direct observations of dislocations.
6475 - Solubility, segregation, and mixing.
8130M - Precipitation.
6155H - Crystal structure of specific alloys.
Key words
chromium alloys -- cobalt alloys -- deformation -- dislocation arrays -- dislocation motion -- dislocation pile ups -- friction -- ion microprobe analysis -- long range order -- nickel alloys -- precipitation -- short range order -- superalloys -- transmission electron microscopy -- X ray diffraction -- TEM -- annealing -- dislocation movement -- dislocation planar arrays -- dislocation pile ups -- gamma phase -- X ray diffraction -- atom probe nanoanalysis -- deformation -- local order -- monocrystalline MC2 superalloy -- short range order -- high friction stresses -- long range ordered -- L1 sub 2 hyperfine precipitates -- 300 K -- 750 degC -- Ni sub 2 CoCr
© EDP Sciences 1996
DOI: 10.1051/mmm:1996106
Local Order and Associated Deformation Mechanisms in the
Phase of Nickel Base Superalloys
Nicole Clement1, Armand Coujou1, Yvonne Calvayrac2, Francois Guillet2, Didier Blavette3 et Stéphane Duval3 1 CEMES-LOE/CNRS, 29 rue Jeanne Marvig, BP. 4347, 31055 Toulouse Cedex, France
2 CECM/CNRS, 15 rue Georges Urbain, 94407 Vitry Cedex, France
3 LMI, URA CNRS 808, UFR Sciences et Techniques, BP. 118, 76134 Mont Saint Aignan Cedex, France
Abstract
Using X-ray diffraction, atom probe nanoanalysis, T.E.M.
associated with in situ
deformation, the presence of local order in the matrix of a monocrystalline MC2
superalloy is demonstrated.
In Ni2CoCr the model alloy of this phase, as well as in the MC2 matrix, the existence
at room temperature of a strong short range order of
special point type is
emphasized. It induces high friction stresses opposing the movement of dislocations
which have to propagate in planar arrays in the corresponding materials.
In addition, long range ordered 
hyperfine precipitates appear in the MC1 samples
annealed at
. They induce several pairs of dislocations at the head of the moving
pile-ups in order to cut them.
8130B - Phase diagrams of metals and alloys.
6170J - Etch pits, decoration, transmission electron microscopy and other direct observations of dislocations.
6475 - Solubility, segregation, and mixing.
8130M - Precipitation.
6155H - Crystal structure of specific alloys.
Key words
chromium alloys -- cobalt alloys -- deformation -- dislocation arrays -- dislocation motion -- dislocation pile ups -- friction -- ion microprobe analysis -- long range order -- nickel alloys -- precipitation -- short range order -- superalloys -- transmission electron microscopy -- X ray diffraction -- TEM -- annealing -- dislocation movement -- dislocation planar arrays -- dislocation pile ups -- gamma phase -- X ray diffraction -- atom probe nanoanalysis -- deformation -- local order -- monocrystalline MC2 superalloy -- short range order -- high friction stresses -- long range ordered -- L1 sub 2 hyperfine precipitates -- 300 K -- 750 degC -- Ni sub 2 CoCr
© EDP Sciences 1996