Texture evolution and slip mode of a Ti-5.5Mo-7.2Al-4.5Zr-2.6Sn-2.1Cr dual-phase alloy during cold rolling based on multiscale crystal plasticity finite element model

Abstract

The complex micromechanical response among grains remains a persistent challenge to understand the deformation mechanism of titanium alloys during cold rolling. Therefore, in this work, a multiscale crystal plasticity finite element method of dual-phase alloy was proposed and secondarily developed based on LS-DYNA software. Afterward, the texture evolution and slip mode of a Ti-5.5Mo-7.2Al-4.5Zr-2.6Sn-2.1Cr alloy, based on the realistic 3D microstructure, during cold rolling (20% thickness reduction) were systematically investigated. The relative activity of the <112¯0>{0001} slip system in the α phase gradually increased, and then served as the main slip mode at lower Schmid factor (<0.2). In contrast, the contribution of the <112¯3>{101¯1} slip system to the overall plastic deformation was relatively limited. For the β phase, the relative activity of the <111>{110} slip system showed an upward tendency, indicating the important role of the critical resolved shear stress relationship in the relative activity evolutions. Furthermore, the abnormally high strain of very few β grains was found, which was attributed to their severe rotations compelled by the neighboring pre-deformed α grains. The calculated pole figures, rotation axes, and compelled rotation behavior exhibited good agreement to the experimental results.