Constitutive modeling for high-temperature flow behavior of Ti-6242S alloy

The high-temperature deformation behavior of near-alpha Ti-6242S alloy was investigated at temperatures in the range of 850-1000 degrees C and at strain rates of 0.001-1 s(-1). The results indicated a difference in the flow stress behavior of the lower (T <= 950 degrees C) and upper (T = 1000 degrees C) parts of the two-phase alpha/beta region. Dynamic recovery and recrystallization of beta phase occur at 1000 degrees C, while distortion and dynamic globularization of alpha phase are the dominant events, at temperatures lower than 950 degrees C. Flow behavior of the alloy was predicted through developing two phenomenological constitutive models, considering the coupled effects of deformation temperature, strain rate and strain. Furthermore, a comparative study was performed on the capability of the aforementioned models to predict the high-temperature flow behavior of the Ti-6242S alloy. Comparing the predicted average absolute relative error and correlation coefficient showed a more accurate flow behavior through Arrhenius-type equation against to the dynamic softening (Cingara) model. However, a novel approach was used to enhance the Cingara model and was verified with experimental result showing an increase in accuracy.