Les intermétalliques : des superalliages aux quasicristaux
J. Phys. IV France 06 (1996) C2-247-C2-252
Fatigue Crack Propagation Behaviour of a TiAl-based AlloyG. Hénaff, C. Mabru and J. Petit
Laboratoire de Mécanique et de Physique des Matériaux, URA 863 du CNRS, ENSMA, Site du Futuroscope, BP. 109, Chasseneuil du Poitou, 86960 Futuroscope cedex, France
In the present study the fatigue crack propagation resistance of a nearly fully lamellar quaternary TiAl based is investigated at room-temperature. The fatigue crack growth rates material are shown to be highly sensitive on the applied stress intensity factor amplitude. A special attention is also paid to the influence of extrinsic factors. Thus crack-closure is proved to strongly influence the propagation. As regards environmental effects , ambient air induces fatigue crack growth rates two orders of magnitude higher than those measured in vacuum. The role of moisture in this deleterious effect is discussed.
© EDP Sciences 1996