Hot Workability and Microstructural Evolution of Ti-5.5Al-5Mo-5V-2Nb-1Fe-1Zr Titanium Alloy Based on the Different Phase Zones during Plastic Deformation at High Temperatures

Hot workability and microstructural evolution of Ti-5.5Al-5Mo-5V-2Nb-1Fe-1Zr titanium alloy, which is also called Ti555211 titanium alloy, are investigated during compressive deformation at different temperatures and strain rates. It can be found that Ti555211 samples deformed at 750 and 850 degrees C comprised alpha and beta phases, while Ti555211 samples deformed at 950 and 1050 degrees C consist of single beta phase. When Ti555211 sample undergoes compressive deformation in the alpha + beta phase region, microstructures of beta phase vary more substantially than those of alpha phase, which means that plastic deformation of Ti555211 sample is governed by beta phase. The process parameters are optimized by establishing processing maps based on dynamic material model. Ti555211 alloy generally possesses the better hot workability in the beta phase zone. In the beta phase zone of Ti555211 alloy, the best hot process area involves temperature range from 925 to 1025 degrees C and a strain rate range of 0.005 to 0.03 s(-1).

Automated summary

The hot workability and microstructural evolution of Ti-5.5Al-5Mo-5V-2Nb-1Fe-1Zr titanium alloy, also known as Ti555211 alloy, were studied during compressive deformation at different temperatures and strain rates. It was observed that samples deformed at 750 and 850 degrees C consisted of alpha and beta phases, while samples deformed at 950 and 1050 degrees C were composed of single beta phase. The plastic deformation of Ti555211 alloy was mainly governed by the beta phase, as the microstructures of the beta phase varied more substantially than those of the alpha phase in the alpha + beta phase region. Processing maps based on a dynamic material model were established to optimize the process parameters. Ti555211 alloy exhibited better hot workability in the beta phase zone, with the optimal hot processing area ranging from 925 to 1025 degrees C and a strain rate range of 0.005 to 0.03 s(-1).