Hot Deformability of Cast High Nb Containing TiAl Alloy

Abstract:

The hot compressive deformation behaviour of high Nb containing TiAl alloy was investigated in the temperature range of 900~1250 ℃, at the strain rate range of 5×10-4 ~1 s-1 and the engineering strain range of 50%~80% on Gleeble-1500 hot simulator. The flow stress behaviour of high Nb containing TiAl alloy can be represented by a Zener-Hollomon parameter in the exponent style equation. The regressed expression is σp=197.6ln{(Z/9.59×1015)0.285+(Z/9.59×1015)0.570+1}1/2}. The hot deformation activation energy of high Nb containing TiAl alloy during hot deformation is (497±49) kJ/mol. The hot deformability map of cast high Nb containing TiAl alloy was given in this paper.

Key words:high Nb containing TiAl alloy; hot deformation; flow stress; activation energy