Microstructure Evolution and Deformation Behavior of Hydrogenated TC17 Titanium Alloy

In order to improve the hot workability of TC17 titanium alloy, TC17 titanium alloy was hydrogenated. The microstructure and phase transformation law of TC17 titanium alloy were studied by OM and XRD after hydrogenated treatment. Under the conditions of deformation temperature of 800 similar to 860 degrees C and strain rate of 0.001 similar to 0.1 s(-1), the isothermal compression tests of hydrogenated TC17 titanium alloy were carried out. The deformation behavior of the hydrogenated TC17 titanium alloy was studied, and the thermal activation energy was calculated and analyzed. The results show that the microstructure of TC17 titanium alloy is a typical net basket structure, which is composed of alpha+beta phase. With the increase of hydrogen content, the volume fraction of acicular alpha phase decreases, and the volume fraction of beta phase. When the hydrogen content exceeds 0.40wt%, the gamma and delta hydrides separate out. The hydrogenated TC17 titanium alloy is not only a temperature sensitive material, a rate sensitive material, but also a hydrogen content sensitive material. When the hydrogen content is 0.2wt%, the peak stress reaches the minimum value. Compared with the original alloy, the deformation temperature can be decreased by 40 degrees C and the strain rate increases by one order of magnitude. At the same time, the thermal activation energy of TC17 titanium alloy with 0.2wt% hydrogen content also reaches the minimum value of 162 kJ/ mol, and its thermal deformation softening mechanism is dynamic recovery.