The isothermal compression tests of Al-5 Ti-1 B master alloy were conducted on the thermal mechanical simulator Gleeble-1500 D at the deformation temperature range of 300-450 ℃,the strain rate range of 0.01-10.00 s^(-1),and the engineering strain of 50 %.The effects of deformation temperatures and strain rates on the flow stress were analyzed by the true stress-true strain curves.The result indicates that the flow stress increases with the increase of strain rate,while it decreases with the increase of temperature.The hot deformation activation energy of Al-5 Ti-1 B master alloy is calculated to be250.9 kJ·mol^(-1),and the constitutive equation is established as ε= 1.97×10^(19)[sinh(0.015σ)]^(11.14)exp(-250.9/RT),and the validity of this constitutive equation is verified.Based on dynamic material model(DMM) criterion,the hot processing map of Al-5 Ti-1 B master alloy is obtained.The optimum hot extrusion conditions are determined as deformation temperature of 400 ℃ and strain rate of1.00 s^(-1),and the flow instability only appears at the temperature range of 300-340 ℃ at the base of the hot processing map.
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