The Development and Control of Crystallographic Texture in 3Al-2.5V Titanium Alloy Tubing

Crystallographic textures which develop in alpha titanium alloys as a result of cold reduction can cause significant anisotropy or directional properties in finished aircraft hydraulic line tubing. The directional properties can either enhance or detract from tubing fatigue life and formability depending on the type of texture built into the tube during manufacture.

Previous work has shown that the texture associated with optimum tube properties is one for which the basal poles of the hexagonal cell are near perpendicular to the tube axis in the longitudinal section, and radial in the transverse section. This texture is developed by using high ratios of wall to diameter reduction during cold working.

The text provides guideline data for controlling cold reduction schedules during tube making to produce an optimum texture in the final product. Both tube reducing and bench drawing are considered as cold working methods.

A discussion of a relatively fast and simple method for measuring the anisotropy present in tubing is given as a preliminary step toward establishing a standard test which can be used in procurement specifications.