Phase transformation and microstructure evolution of differently processed Ti–45Al–9Nb–Y alloy

Microstructure formation in as-cast, wrought and as-rolled Ti–45Al–9Nb–Y alloys has been investigated, and near lamellar, near duplex and near gamma structures were observed, respectively. The investigation included the evolution of the β/B2-phase in these three differently processed Ti–45Al–9Nb–Y alloys. Omega-phase occurs on the expense of the β/B2-phase in the hot deformed Ti–45Al–9Nb–Y alloy. Moreover, γ laths precipitate in β/B2-phase when the alloy was hot rolled. After canned forging, a tweed like contrast which is perpendicular to the orientation of lamellae occurs in the coarsened α2 laths in residual lamellae. In addition, a rod-like microstructure which is composed of the α2 and γ-phase has been observed in as-rolled alloy. The grain size of this material is a little larger than that of the as-forged alloy, but rather smaller than of the as-cast alloy.