Abstract: Ti-2Al-2.5Zr is widely used in piping and structural support applications, however, the rolling forming process results in anisotropic deformation during service. This behavior has implications for the manu-facturing processes and structural safety assessments in engineering applications. In this study, the plas-tic anisotropic deformation behavior of a rolled Ti-2Al-2.5Zr plate was investigated using uniaxial tensile tests along the transverse, normal, and 45 °directions. Acoustic emission, electron backscatter diffraction, and scanning electron microscopy methods were used to investigate dislocation slip and twinning mech-anisms. The results indicated that different microscopic deformation mechanisms caused the significant macroscopic anisotropy of Ti-2Al-2.5Zr. The primary mechanisms involved were prismatic <a> slip, pyra-midal <c+a> slip, and {10-12} extension twinning. The stress direction determined the influence of each of these mechanisms during the yielding and plastic deformation phases. Application of the visco-plastic self-consistent model established the relationship between the macroscopic mechanical responses and microscopic deformation mechanisms. It was revealed that Ti-2Al-2.5Zr achieved its optimum strength when the initial texture aligned most of the grain c-axis at angles ranging from 30 °to 50 °relative to the deformation direction. This finding provides a direction for the texture design of Ti-2Al-2.5Zr in engineer-ing materials.

Key words: Anisotropy, Extension twinning, Plastic deformation, Ti-2Al-2.5Zr titanium alloy, VPSC model