Study of Deformation Mechanisms of a High-Purity α-Titanium Plate Under Monotonic Loading with the EVPSC-TDT Model

The deformation mechanisms of a rolled high-purity α-titanium plate under monotonic loading along the rolling direction (RD), transverse direction (TD), and normal direction (ND) are investigated by the Elastic Visco-Plastic Self-Consistent (EVPSC) model, which incorporates a Twinning and De-Twinning (TDT) scheme to describe twinning behavior during straining. In the EVPSC-TDT model, plastic deformation is assumed to be accommodated by prismatic, basal and pyramidal c+a$$\left\langle {{\text{c}} + {\text{a}}} \right\rangle$$ slip modes as well as the 101¯2$$\left\{ {10\bar{1}2} \right\}$$ extension and 112¯2$$\left\{ {11\bar{2}2} \right\}$$ contraction twin modes. Numerical results based on the EVPSC-TDT model are in good agreement with the corresponding experimental data. The tension–compression asymmetry, anisotropic initial yielding and strain hardening behavior are interpreted in terms of the predicted relative activities of various deformation modes, twin volume fractions and texture evolutions. It is demonstrated that twinning plays an important role in tension–compression asymmetry and plastic anisotropy, which is closely related to the loading direction with respect to crystal orientations in the initial texture. In addition, it can be concluded that the TDT scheme permits better performance in describing twinning-associated deformation behavior for the rolled high-purity α-titanium plate than the Predominant Twin Reorientation (PTR) model even when detwinning is not involved.Graphical abstract