Hot Deformation Behavior and Processing Map of β-CEZ Titanium Alloy

The hot deformation behaviors of beta-CEZ alloy in the temperature range of 800 similar to 1000 degrees C and strain rate range of 0.01 similar to 10 s(-1) were studied by hot compressing testing on a Gleeble-3800 simulator at the deformation degree of 0.7. The high temperature deformation behavior, the flow instability and the deformation mechanism in alpha+beta phase field and beta phase field were studied by true stress-true strain curves and processing maps, which were established based on experimental data and Prasad criterion. Results indicate that under the experimental conditions, beta-CEZ titanium alloy shows two kinds of softening mechanism, dynamic recovery and recrystallization. With the increase of strain, the flow stress decreases slowly in alpha+beta phase field after the peak stress; in beta phase field discontinuous yielding occurs after the peak stress, and the flow stress decreases rapidly before reaching a constant state. The domain with high value of the efficiency of power dissipation (eta) at alpha+beta phase field is 850 similar to 890 degrees C/0.01 similar to 0.05 s(-1), which is the spheroidization of a lamellae area. And the domain with high value of the efficiency of power dissipation (eta) at beta phase field is 940 similar to 980 degrees C/0.2 similar to 0.6 s(-1), which is the dynamic recrystallization area. The domains of flow instability are 800 similar to 850 degrees C/0.1 similar to 10 s(-1), 850 similar to 900 C/0.1 similar to 5 s(-1) and 900 similar to 1000 C/1 similar to 10 s(-1). The manifestation of the flow instability is adiabatic shear band at the alpha+beta phase field, while it is non-uniform deformation at the beta phase field.