The interest in titanium aluminide alloys includes elevated temperature applications, for which creep resistanc~i s a primary property. Tests have been madebetween 650 and 870'C on a variety of microstructures of Ti-24Al-1 1 Nb and Ti-25Al-10Nb-3M0-1V (ato/o) where i* is the steady-state creep rate at a tensile stress cr, n and A are constants, Q, is the apparent activation energy. R the gas constant, and T the absolute temperature. Therefore, plotting log of steady-state creep rate vs. Iog a will result in a straight line with a slope equal to n, the power-1aw exponent.25~27)The results for the role of microstructure for both Ti-24-11 and Ti-25-10-3-1 can be illustrated with the two examples in Fig. 3 From Ref, 16 Temperature Dependence In addition to the stress exponent n, the apparent activation energy Q, is considered helpful29,35) in establishing the controlling mechanismof creep deformation.In Fig. 5