Fine-grained structure fabricated by strain-induced martensite and its reverse transformations in a metastable β titanium alloy

Submicron-sized β grains were attained in a metastable βTi77.5V15.9Al3.6Sn3.0 alloy through the strain-induced martensite and its reverse transformations process, characterized by a single cycle of conventional cold rolling and annealing. The grain refinement was attributed mainly to the reverse-transformed β grains from nanosized α′′ and α phases. During the continuous heating of the cold-rolled specimen, the β to α transformation occurred first, and α′′ to β and α to β reverse transformations took place sequentially.

► Submicron-sized β grains were attained in a metastable β Ti77.5V15.9Al3.6Sn3.0 alloy.
► Grain refinement was attributed mainly to reverse transformation of α′′ and α to β.
► Relationship between dilatational changes and phase transformations was examined.