Effect of hot-deformation on the microstructure of the Ti–Al–Nb–W–B alloy

A large ingot (15 kg) produced through the magnetic-flotation-melting method with the composition of Ti-45Al-7Nb-0.15B-0.4W, in atomic percent (at.%), tends to have a larger grain size of ∼110 μm and a larger amount of the β-phase in the alloy ingot when compared with the small drop-casted specimen (0.15 kg), which has a fine grain size of ∼50 μm. Through the application of additional thermo-mechanical treatment, such as hot forging, the amount of the residual β-phase in the large ingot alloy can be effectively reduced; the grain size of the alloy can be refined. The relationship among the hot working, heat treatments, and microstructures of the TiAl-based alloy has been investigated.