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 ℃ 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℃) and upper (T=1000℃) parts of the two-phase alpha/beta region. Dynamic recovery and recrystallization of beta phase occur at 1000℃, while distortion and dynamic globularization of alpha phase are the dominant events, at temperatures lower than 950℃. 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.