Understanding processing map and microstructural evolution of powder metallurgy Ti-6Al-4V within a wide range of deformation temperatures

The hot deformation behavior and microstructural evolution of powder metallurgy (PM) Ti-6Al-4V are investigated using the Arrhenius constitutive model, hot processing map, microstructure observation, and hot deformation mechanism analysis. The optimal processing parameters obtained from the hot processing map are 1323–1423 K at 0.1–1 s−1, and 1423–1523 K at 1–10 s−1. Hot deformation in β region is attractive for PM Ti-6Al-4V. The dominant hot deformation mechanism of PM Ti-6Al-4V is dynamic recrystallization (DRX) in the (α + β) and β regions. Continuous dynamic recrystallization (CDRX) is the dominant mechanism in the (α + β) region. The combination of CDRX and discontinuous dynamic recrystallization (DDRX) is the preferred mechanism in the β region. The power-dissipation efficiency is affected by DRX, which consumes dislocations and refines the microstructure. Specific hot working parameters for thermomechanical processing (TMP) of PM Ti-6Al-4V are identified. [Display omitted] •Proper hot working parameters for the thermomechanical processing are identified.•Hot deformation of PM Ti-6Al-4V was more effective in the β region than in the (α + β) region.•Undesired microstructure and hot working parameters have been addressed.•The dominant hot deformation mechanism is dynamic recrystallization.