Effect of high strain rate beta processing on microstructure and mechanical properties of near- titanium alloy Ti-10V-2Fe-3Al

The article presents microstructures and mechanical properties of near- Ti-10V-2Fe-3Al titanium wrought alloy after two differentiated processing cycles. The assumed processing paths involved high strain rate hot deformation in -phase range, followed by solution treatment with variation of cooling rate and subsequent single or double aging. To estimate the effects of the assumed treatment cycles, optical microscopy and scanning electron microscopy microstructure analysis was conducted, with special attention paid to evolution of alpha precipitates in consecutive stages of processing and their role in grain refinement. The correlation between tensile properties and grain size, as well as the amount of precipitates amount was found to be connected with alpha-plates' size and morphology. It was concluded that in case of Ti-10V-2Fe-3Al titanium alloy, proposed cycles of thermomechanical processing allow reduction of inhomogeneous recrystallization resulting in necklace substructure. On the other hand, high strain rate promotes mechanical properties improvement, as it favors fragmentation of continuous grain-boundary precipitates.