Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
J. Phys. IV France 03 (1993) C7-441-C7-444
Characterizing faulted dipoles in TiAl with electron microscopy and computed image simulationsB. VIGUIER, K.J. HEMKER, R. SCHÄUBLIN and J.L. MARTIN
Institut de Génie Atomique, Ecole Polytechnique Fédérale, 1015 Lausanne, Switzerland
The low temperature deformation microstructure of TiAl is dominated by the presence of stacking fault dipoles . Two different faulted dipole geometries have been proposed in the literature [2,3], and the existence of both types of faulted dipoles have been verified in the present study with comparisons to computer simulated images. These comparisons suggest that extrinsic stacking faults in TiAl are bounded by single Shockley partial dislocations when the deformation occurs at room temperature and by double Shockley partial dislocations when the deformation occurs at 80 K. This change in the faulted dipole geometry is believed to be related to a change in the activity of the super dislocations that control deformation.
© EDP Sciences 1993