Hot-Workability of Gamma-Based TiAl-Alloys during Severe Torsional Deformation

Abstract

Wrought TiAl products manufactured by conventional hot-working procedures, such as forging and extrusion, suffer from structural and chemical inhomogeneities, which are major concerns for the reliability of components. In an attempt to overcome these problems, TiAl alloys were hot worked by torsional deformation. Using this method, a much higher strain and mechanical work can be imparted, which triggers dynamic recrystallization. The metallurgical potential of this technique will be assessed. Particular emphasis is placed on shear localization processes, which often lead to premature failure of the workpiece.