Grain refinement of intermetallics by severe plastic deformation

Gamma titanium aluminides (γ-TiAl) of compositions Ti–(42, 48, and 52)at.% Al were deformed to strains >100% by equal channel angular extrusion (ECAE) at temperatures <1100 °C with the objective of producing sub-micrometer grains by either concurrent or post deformation recrystallization. ECAE processing produced 1–2 μm grains—an order of magnitude smaller than in conventionally processed titanium aluminides. The grain refinement was the result of dynamic recrystallization during ECAE processing. ECAE processed titanium aluminides exhibited increased bend ductility.