ISSN:
1573-2746
Keywords:
interfaces
;
superalloys
;
“in situ”
;
transmission electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract “In situ” transmission electron microscopy observations of the dislocation motion at vicinity of the γ/γ' interfaces in a Ni-base superalloy have been performed. They allow to identify the elemental mechanisms, under stress and at different temperatures, of the deformation propagation across the interfaces. It is shown that some of the mechanisms already analyzed in the literature occur. Moreover, new processes are revealed such as the formation of small dislocation pile-ups on the γ/γ' interfaces. Such a configuration, which increases the local stress, favors the overcoming of the interface. These observations together with new considerations on stresses are taken into account for proposing a new equilibrium equation for a dislocation abutting on a γ/γ' interface. This equation involves all the stress components acting on a dislocation: the applied stress, the misfit stress, the friction stress, the stress concentration due to the dislocation pile-up and the image stress.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00240250
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