LAUSR

In this work, the impact of the microstructure and the loading conditions on the mechanical behavior of a β -rich Ti17 titanium alloy is investigated. For this purpose, two different initial microstructures are considered : (i) a two-phase lamellar α  +  β microstructure and (ii) a single-phase equiaxed β -treated microstructure. First, compression tests are performed at different strain rates (from $$10^{-1}$$ 10 - 1 to 10 s −1 ) and different temperatures (from 25 to $$900\,^\circ $$ 900 ∘ C) for both microstructures. Then, optical microscopy, scanning electron microscopy, EBSD and X-ray diffraction analyses of deformed specimens are carried out. Whatever the loading conditions are, the flow stress of the as-received α  +  β Ti17 is higher than that of the β -treated Ti17. Also, because of a higher strain-rate sensitivity, the β -treated Ti17 is less prone to shear banding. At low temperatures (i.e., $$T \le 450\,^\circ $$ T ≤ 450 ∘ C), the deformation behavior of both the as-received α  +  β and the β -treated Ti17 is controlled by strain hardening. For the β -treated Ti17 alloy, martensitic transformation is systematically detected in this temperature range. The softening behavior of the as-received α  +  β Ti17 observed at high temperatures is due to the joint effect of dynamic recrystallization, dynamic transformation, adiabatic heating and morphological texture evolution. For the β -treated Ti17 alloy, when the temperature exceeds $$700\,^\circ $$ 700 ∘ C, stress–strain curves display a yield drop phenomenon, which is explained by dynamic recrystallization.