Characterization of Hot Deformation Behavior of a New Near-β Titanium Alloy: Ti555211

Abstract

AbstractThe deformation behavior of an isothermally compressed Ti555211 titanium alloy was examined by an Arrhenius-type constitutive model using experimental data obtained from hot compression tests; these tests were performed at temperatures and strain rates of 750–950°C and 0.001–1 s−1, respectively. Activation energies of hot deformation were calculated in 0.05 intervals for strains ranging from 0.1 to 0.7. The respective values of were obtained for the (α+β) and β region. In addition, the predictive capability of the model was described by the average absolute relative error (AARE) and the correlation coefficient (R). The simulated values were compared with the experimental values, and R and AARE of 0.99084 and 6.914%, respectively, were obtained for the Arrhenius-type constitutive model. These values were indicative of the good predictive capabilities of the developed strain-compensated constitutive equation. Moreover, in this work isothermal compression tests, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) were used to systematically investigate the high-temperature deformation behavior of Ti555211 alloy under different processing conditions. EBSD and TEM were used to reveal the substructure and grain orientation of samples of the hot-deformed Ti555211 alloy. The phenomenon of discontinuous yielding was also discussed.