The high-temperature flow behavior of TCll/Ti-22Al-25 Nb electron beam（EB） weldments was investigated by the isothermal compression tests at the temperature of 900-1060℃ and the strain rate of 0.001-10 s-（-1）.Based on the experimental data,the constitutive equation that describes the flow stress as a function of strain rate and deformation temperature is obtained.The apparent activation energy of deformation is calculated,which decreases with increasing the strain and the value is 334 kJ/mol at strain of 0.90.The efficiency of power dissipation η changes obviously with the variation of deformation conditions.Under the strain rates of 0.01,0.1 and 1 s-（-1）,the value of η increases with increasing the true strain for different deformation temperatures.While the value of η decreases with increasing the strain under the strain rates of 0.001 and 10 s-（-1）.The optimum processing condition is（t（opi）=1060℃,ε（opi）=0.1 s-（-1）） with the peak efficiency of 0.51.Under this deformation,dynamic recrystallization（DRX） is observed obviously in the microstructure of welding zone.Under the condition of 1060℃ and 0.001 s-（-1）,the deformation mechanism is dominated by dynamic recovery（DRV） and the value of η decreases sharply（η=0.02）.The flow instability is predicted to occur since the instability parameter ξ（ε）becomes negative.The hot working process can be carried out safely in the domain with the strain rate of 0.001-0.6 s-（-1） and the temperature of 900-1060℃.
