Refining grain size of a TiAl alloy by cyclic heat treatment through discontinuous coarsening

Recently, we reported a novel approach for grain refinement of TiAl alloys by cyclic heat treatment (CHT) only. Different from our previous studies involving fast cooling, in this study, an alternative CHT route is provided for grain refinement under relatively slow cooling. It is particularly shown that a coarse fully lamellar structure can be refined to a fine one with a size of ∼30 μm. The underlying mechanism for the refinement involves discontinuous coarsening reaction during CHT.