Microstructure Formation in Cast Beta-Solidifying Gamma-Titanium Aluminide Alloys

Abstract

In view of the development of improved TiAl cast alloys the potential of the beta/alpha transformation and its dependence on the addition of several alloying elements has been investigated. It was found that microstructural refinement in beta solidifying alloys can be attributed to the alloying effect on the kinetics of the beta/alpha transformation. This also holds for grain refinement through Borides which apparently serve as nucleation sites for the alpha phase in the solid-state transformation.