Texture Development in α+ß Titanium Alloys

Abstract

Textures arise as a result of extensive plastic deformation, usually in one direction, and may be modified or strengthened by subsequent recrystallization annealing. In titanium alloys where the hexagonal phase predominates, the textures which develop are usually described in terms of the orientation of the basal plane (0001). The basal textures which develop in titanium alloys can be broadly classified as those in which the basal planes are parallel with the rolling plane (Figure 1(a) and those in which the basal planes are normal to the rolling plane (Figure 1(b)). The former textures are well documented to result in improved biaxial strength properties (References 1,2, and 3). The latter textures, by contrast, produce mechanical property anisotropy in the rolling plane (References 4, 5, and 6). Recognizing our intent to provide enhanced structural integrity in a single product direction, our research effort focused on providing better description of how Figure 1 (b) or basal transverse textures form and the properties such a textured material exhibits. The alloy we elected to employ in the program is 6A1-4V Ti. We shall report on results obtained with two heats of metal containing either 0.09 wt% oxygen (ELI Grade) or 0.15 wt% oxygen (Standard Grade). In all other respects, the alloy chemistries of these two heats was identical.

Research sponsored by the United States Air Force Materials Laboratory under Contract F33615-74-C-5107