Research on the anisotropic mechanism of plastic behavior during tensile process of textured pure titanium

Abstract

The presence of texture has an important influence on the deformation behavior of titanium. In this study, the anisotropy of the macro-mesoscopic deformation behavior of the material and its evolution with strain were systematically studied by uniaxial tensile test and electron backscatter diffraction (EBSD) technique. Based on the above results, the calculation formula of Schmid factor (SF) for each variant of the slip system expressed by the crystal orientation angle was derived, and the influence of initial texture and texture redirection on the activability of each deformation mode was explored. The impact of the ratios between the critical resolved shear stress (CRSS) of the three deformation modes on the predictions of the dominant deformation mode of yield was systematically assessed, using the CRSS as the standard. The initial yield mode of RD tensile is prismatic <a>slip, while TD tensile may be a combination of multiple slip modes. One of the primary reasons of the evolution of the basal split texture components is the activation of dislocation slip, while the twinning mainly plays a role in coordinating the deformation. According the Taylor axis analysis, the prismatic <a> slip is the primary deformation mode during RD and TD tensile, followed by pyramidal <a> slip, while the basal <a> slip is difficult to be activated or the activability decreases with the increase of strain.