Influence de la teneur en oxygène sur le comportement au fluage d'alliages Ti-48Al

Abstract
The influence of oxygen on microstructure and creep behaviour of Ti-48Al alloys is investigated. The metallurgical structure of the samples is essentially lamellar in spite of the appearance of small grains at the grain boundaries for the high purity alloy. Therefore, the presence of oxygen allows a stabilisation of the lamellar phase. Micro-hardness does not seem to depend on the content of oxygen but rather on the lamellar nature of these alloys. On the other hand, the presence of oxygen promotes creep resistance, whereas that of Mn and Nb reduces the extent of the secondary creep stage.