Texture development of Ti-3Al-2.5V titanium alloy tubes

Abstract:

The anisotropy, which is one of key mechanical properties of Ti-alloy tubes, is usually described in terms of the contractile strain ratio (CSR) macroscopically and dependent on the micro texture evolution. In order to understand the variation of CSR, the texture evolution of Ti-3Al-2.5V titanium alloy tubes is studied by Electron Back-Scattered Diffraction (EBSD). The results show that the basal poles of the α-phase inclined from the radial direction to circumferential direction and stabilized around 45° between these two directions, and the strongly preferred orientation of the β-phase was observed with the increase of axial plastic strain. This change of texture causes the CSR values to decrease rapidly in the initial stage, then decrease slowly until stabilizing in the final stage. The simple model between CSR and texture quantity parameter f is modified by incorporating the texture component in the axial direction. Comparison with experiment shows that the modified model is in better agreement with the experimental values than the simple model.

Key words:Ti-3Al-2.5V; texture development; contractile strain ratio; anisotropy