Deformation of Ti-6Al-4V Bar and Extrusion under Superplastic Forming Conditions

摘要

There is increasing interest in the use of conventional product forms such as her and extrusions for superplastic forming (SPF) of pressure vessels and tubular body shells. Tests have been carried out to compare the superplasticity of Ti-6Al-4V bar and extrusion with that reported for sheet. The flow stresses, m-values and plastic anisotropy were measured and related to the microstructure. Resulting anisotropy occurred in specimens machine both parallel (L) and perpendicular (T) to the extrusion major axis. Anisotropy also occurred in specimens machine perpendicular (T), but not parallel (L) to the bar major axis. The anistropy can be explained in terms of the directionality of the microstructure. It is concluded that for limited strains these conventional product forms, although having non-ideal microstructures can be suitable for superplastic forming of components. Great Britain. (JES)