Investigation of High-Temperature Constitutive Behavior of Ti555211 Titanium Alloy Subjected to Plastic Deformation in the Different Phase Regions

Ti555211 titanium alloy is subjected to plastic deformation in the dual-phase (alpha + beta phase) zone and single-phase (beta phase) zone at various deformation temperatures and strain rates. High-temperature constitutive equations of the alloy in the dual-phase zone and single-phase zone are established in order to describe deformation behavior of the alloy in the different phase zones. By comparing the constitutive equation of the alloy in the dual-phase zone with that of the alloy in the single-phase zone, the deformation activation energy of the former was found to be higher than that of the latter. It is obvious that the deformation activation energy of alpha phase is obviously greater than that of beta phase. Furthermore, the microstructural evolution of the alloy is different in the dual-phase zone and single-phase zone. When the alloy was subjected to plastic deformation in the dual-phase zone, the size of the grains in the beta phase increased with the decreasing strain rate. When the alloy was subjected to plastic deformation in the single-phase zone, the size of the grains in the beta phase considerably increased with the increasing deformation temperature. In particular, in the microstructures of the alloy subjected to plastic deformation in the single-phase region, the elongated grains can be observed at higher strain rates. Furthermore, it is more difficult for the alloy to induce plastic deformation in the dual-phase region than in the single-phase region.

Automated summary

The plastic deformation behavior and microstructural evolution of Ti555211 titanium alloy in different phase zones have been studied. Different deformation activation energies are observed in the dual-phase and single-phase zones, with the former having a higher energy for deformation. Moreover, the size of beta phase grains increases with decreasing strain rate in the dual-phase zone, while it increases significantly with increasing deformation temperature in the single-phase zone. Elongated grains are observed in the microstructures of the alloy subjected to plastic deformation in the single-phase region at higher strain rates. Additionally, it is more difficult for the alloy to induce plastic deformation in the dual-phase region than in the single-phase region.