Deformation behaviour of commercially pure titanium at extreme strain rates

The evolution of microstructure and texture during room temperature compression of commercially pure Ti with four different initial orientations were studied under quasi-static and dynamic loading conditions. At a low strain rate ε˙ = 3 × 10−4 s−1 all the different initial textures yielded the same end texture, despite different microstructural evolution in terms of twin boundaries. High strain rate deformation at ε˙ = 1.5 × 103 s−1 was characterized by extensive twinning and evolution of a texture that was similar to that at low strain rate with minor differences. However, there was a significant difference in the strength of the texture for different orientations that was absent for low strain rate deformed samples at high strain rate. A viscoplastic self-consistent model with a secant approach was used to corroborate the experimental results by simulation.

Research highlights
► Deformation texture is weaker for high strain rate deformation.
► Basal oriented sample undergoes minimum twinning and exhibits least hardening.
► Difference in hardening for different orientations reduces at high strain rate.
► Basal slip is active during the course of deformation.
► Extent of slip is more than twinning at all strain rates for all orientations.