Precipitation behavior of a β-quenched Ti-5Al-5Mo-5V-1Cr-1Fe alloy during high-temperature compression

The precipitation behavior of a phase in a beta-quenched Ti-55511 alloy during high-temperature compression is investigated. The influences of deformation parameters on the flow characteristics, microstructural evolution, as well as the precipitation behavior of a phase, are discussed. Results show that the flow stress features and the dominant softening mechanism are sensitive to the deformation parameters. At low strain rates or high deformation temperatures, the main softening mechanism is dynamic recovery. But, the dynamic recrystallization becomes the dominant softening mechanism at high strain rates or low temperatures. At low strain rates, the continuous strengthening, induced by the pinning effect of a precipitates, happens at the late period of deformation. Distribution of alpha precipitates is not greatly affected by deformation parameters. In the region near beta grain boundary, a precipitates are densely distributed with few orientations. While in the central region of beta grain, the a precipitates are distributed a bit more sparsely with several scattering orientations. In addition, with increasing deformation temperature, the content, aspect ratio and size of a phases decrease. However, with increasing strain rate, the content, aspect ratio and size first increase and then decrease. Furthermore, the peak value of aspect ratio appears at 0.01 s(-1).