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Interface Related Strength Phenomena in Two-Phase Titanium Aluminides

Published online by Cambridge University Press:  10 February 2011

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

Phase equilibria and transformations in near-equiatomic titanium aluminides lead to the formation of a lamellar structure comprising of the intermetallic phases α2(Ti3Al) and γ(TiAl). Due to the differences in lattice parameters and crystal structure, coherency stresses and mismatch structures occur at various types of semicoherent interfaces present in the material. The present paper reports an electron microscope study of the atomic structure of the interfaces. The residual coherency stresses present at the interfaces were determined by analysing the curvature of dislocation loops which were emitted from the network of interfacial dislocations. The implication of these stresses on creep will be discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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References

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