Deformation microstructures of γ-TiAl in the Ti-46Al-2V alloy

Majority of the dislocations present in samples deformed at various temperatures are of b = 12 < 110] type. They are generally mixed in character, and therefore would have higher mobility than those pure screw type. Very few isolated b = 12 < 112] dislocations are observed in the elevated temperature deformation microstructure. This may be due to the fact that they experience much higher Peierls stress than the b = 12 < 110] dislocation owing to their larger Burgers vector than that of b = 12 < 110] dislocations. The number of b = < 101] superdislocations at high temperature is quite low, and this is probably due to their low mobility caused by the formation of Kear-Wilsdorf (12) type of locks. Dislocation loops can also be seen in the elevated temperature deformation microstructures, and they are associated with the b = 12 < 110] curved and tangled dislocations. They form due to the interactions of the b = 12 < 110] dislocations. The density of twins in the samples is quite high, and it appears to increase with the increasing deformation temperature. The deformation microstructures of the alloys studied here are similar to those observed in the binary two-phase (α2 + γ) titanium aluminides, and it appears that V does not significantly change the deformation microstructures of this particular alloy.