Grain refinement of a Ti-47Al-8Nb-2Cr alloy through heat treatments

The grain size of the fully lamellar structure of alloy Ti-47Al-8Nb-2Cr was refined from 500 μm to 30 μm through heat treatments only. Such refinement was achieved through air cooling, which is slower than those used for alloy Ti-47Al-2Nb-2Cr. This is attributed to the effect of a high-Nb content on promoting massive transformation.