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Title: Transmission electron microscopy study of dislocation-dispersoid interaction in deformed Incoloy MA956

Abstract

Oxide dispersion strengthened (ODS) FeCrAl alloys exhibited not only excellent corrosion resistance, but also good mechanical properties at high homologous temperatures. The strength of these materials results from a fine dispersion of incoherent oxides which act as non-shearable barriers to dislocation movement. The mechanism of interaction between the dispersoid and dislocations has been of considerable interest in recent years. The creep behavior of ODS alloys has been characterized by a ``threshold stress``; the measured creep rates at stresses slightly above and slightly below the threshold stress differ by many orders of magnitude. There is evidence that for ODS alloys the experimentally determined value of the threshold stress is lower than that calculated using the Orowan model of dislocation-particle interactions. This suggests that there may be an additional type of interaction mechanism. A reasonable value of the threshold stress has been obtained under the assumption of local climb of dislocations at the particles and an attractive dislocation-particle interaction. This microscopic mechanism of creep should lead to dislocations following the curvature of the particle shape at the departure side of the dispersoid. For Ni-base ODS alloys, there is experimental evidence for such a configuration of dislocations. Using transmission electron microscopy (TEM), Nardonemore » and Tien, Schroeder and Arzt and Herrick et al. have shown dislocations pinned at the departure side of particles. A similar result was obtained by Preston et al. for a ferritic ODS alloy (DT2023Y05). The aim of this study was to investigate the configuration of dislocations near dispersoid particles in the commercial ferritic ODS alloy Incoloy MA956.« less

Authors:
; ;  [1];  [2]
  1. Univ. of Mining and Metallurgy, Krakow (Poland). Faculty for Metallurgy and Materials Science
  2. KFA, Juelich (Germany). Inst. for Materials in Energy Systems
Publication Date:
OSTI Identifier:
231106
Resource Type:
Journal Article
Journal Name:
Scripta Metallurgica et Materialia
Additional Journal Information:
Journal Volume: 32; Journal Issue: 3; Other Information: PBD: 1 Feb 1995
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; IRON BASE ALLOYS; DISLOCATIONS; TRANSMISSION ELECTRON MICROSCOPY; CHROMIUM ALLOYS; ALUMINIUM ALLOYS; INCOLOY ALLOYS; EXPERIMENTAL DATA; YTTRIUM OXIDES; TITANIUM ADDITIONS; SPATIAL DISTRIBUTION

Citation Formats

Czyrska-Filemonowicz, A, Wrobel, M, Dubiel, B, and Ennis, P J. Transmission electron microscopy study of dislocation-dispersoid interaction in deformed Incoloy MA956. United States: N. p., 1995. Web. doi:10.1016/S0956-716X(99)80060-0.
Czyrska-Filemonowicz, A, Wrobel, M, Dubiel, B, & Ennis, P J. Transmission electron microscopy study of dislocation-dispersoid interaction in deformed Incoloy MA956. United States. https://doi.org/10.1016/S0956-716X(99)80060-0
Czyrska-Filemonowicz, A, Wrobel, M, Dubiel, B, and Ennis, P J. 1995. "Transmission electron microscopy study of dislocation-dispersoid interaction in deformed Incoloy MA956". United States. https://doi.org/10.1016/S0956-716X(99)80060-0.
@article{osti_231106,
title = {Transmission electron microscopy study of dislocation-dispersoid interaction in deformed Incoloy MA956},
author = {Czyrska-Filemonowicz, A and Wrobel, M and Dubiel, B and Ennis, P J},
abstractNote = {Oxide dispersion strengthened (ODS) FeCrAl alloys exhibited not only excellent corrosion resistance, but also good mechanical properties at high homologous temperatures. The strength of these materials results from a fine dispersion of incoherent oxides which act as non-shearable barriers to dislocation movement. The mechanism of interaction between the dispersoid and dislocations has been of considerable interest in recent years. The creep behavior of ODS alloys has been characterized by a ``threshold stress``; the measured creep rates at stresses slightly above and slightly below the threshold stress differ by many orders of magnitude. There is evidence that for ODS alloys the experimentally determined value of the threshold stress is lower than that calculated using the Orowan model of dislocation-particle interactions. This suggests that there may be an additional type of interaction mechanism. A reasonable value of the threshold stress has been obtained under the assumption of local climb of dislocations at the particles and an attractive dislocation-particle interaction. This microscopic mechanism of creep should lead to dislocations following the curvature of the particle shape at the departure side of the dispersoid. For Ni-base ODS alloys, there is experimental evidence for such a configuration of dislocations. Using transmission electron microscopy (TEM), Nardone and Tien, Schroeder and Arzt and Herrick et al. have shown dislocations pinned at the departure side of particles. A similar result was obtained by Preston et al. for a ferritic ODS alloy (DT2023Y05). The aim of this study was to investigate the configuration of dislocations near dispersoid particles in the commercial ferritic ODS alloy Incoloy MA956.},
doi = {10.1016/S0956-716X(99)80060-0},
url = {https://www.osti.gov/biblio/231106}, journal = {Scripta Metallurgica et Materialia},
number = 3,
volume = 32,
place = {United States},
year = {1995},
month = {2}
}