Microstructural refinement of a TiAl alloy by a two step heat treatment

Microstructural transformation via multi-step heat treatments on a Ti-45Al-(5-10)Nb at.% alloy has been studied. A significant refinement of the microstructure of the alloy has been achieved by a two step heat treatment. Discontinuous coarsening seems to play an important role in the transformations obtained, but can not explain all the microstructural features observed, so other mechanisms should be considered.