Effect of texture and temperature gradient on anisotropic plastic deformation of commercially pure titanium at room and low temperatures

This paper describes a study of deformation anisotropy of rolled grade 1 commercially pure titanium (CP-Ti) in the temperature range -115–20 °C. The tensile experiments combined with DIC technique were performed with samples dipped in liquid nitrogen for ~15 min. Electron backscatter diffraction (EBSD) was effectively used to characterise the microstructure evolution with respect to the extent of deformation. The experimental results and DIC-based analysis presented the texture-dependent plastic anisotropy showing the uniform cross-section reduction and strain localisation. The twinning-induced hardening was responsible for the anisotropic plastic behaviours. The low deformation temperature and increasing temperature gradient during deformation intensified the plastic anisotropy and twinning activity, and possibly increased the activation rate of slips. Consequently, the improvement and deterioration of ductility was observed under the two different crystallographic textures with the plastic anisotropy intensified by the temperature-related effects. These findings are important for understanding the deformation mechanisms of titanium at low temperature, and potentially could lead to improve its formability by conducting low temperature processing (e.g., cryorolling).