Static tensile and creep tests were conducted on Ti-64 (α+β) and β single-phase Ti-15-3 to confirm the effect of the β phase for Ti alloys. Both tests were conducted in a scanning electron microscope (SEM), and strain distribution within the observation area was measured by a digital image correlation (DIC) method. With respect to Ti-64 (α+β), the influence of β phase was not clearly observed in the tensile and creep tests. The crystallographic orientation distribution of α phase strongly affected the deformation behavior and strain distribution. For the deformation behavior of Ti alloys with α+β phases, it is sufficient to consider only the crystallographic orientation distribution of the α phase. On the other hand, Ti-15-3 (β single-phase) formed slip zones along the direction of 45° to the loading line in both tensile and creep tests, which coincided with the macroscopic shear zones. This is primarily because β phase (BCC) has multiple slip systems and little plastic anisotropy. For the deformation behavior of β single-phase Ti alloys, there is little need to focus on the plastic anisotropy caused by the crystallographic orientation.
