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An Electron Microscope Study of Diffusion Assisted Dislocation Processes in Intermetallic Gamma TiAl

Published online by Cambridge University Press:  10 February 2011

F. Appel
Affiliation:
Institute for Materials Research, GKSS-Research Centre, Max-Planck-Strasse, D-21502 Geesthacht, Germany
U. Lorenz
Affiliation:
Institute for Materials Research, GKSS-Research Centre, Max-Planck-Strasse, D-21502 Geesthacht, Germany
M. Oehring
Affiliation:
Institute for Materials Research, GKSS-Research Centre, Max-Planck-Strasse, D-21502 Geesthacht, Germany
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Abstract

The paper reports an electron microscope study of diffusion controlled deformation mechanisms in two-phase titanium aluminides which apparently cause the degradation of the strength properties at elevated temperatures. Climb velocities were analyzed in terms the critical vacancy supersaturation necessary for the operation of diffusion assisted dislocation sources. Particular emphasis was paid on structural changes occurring during long-term creep, which are apparently associated with dislocation climb.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

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