High-temperature deformation behaviors of Ti–2Al–9.2Mo–2Fe alloy with boron

Hot deformation behaviors of Ti–2Al–9.2Mo–2Fe alloy with boron were investigated in a hot compression test at temperatures ranging from 850 to 1000 °C and strain rates ranging from 0.01 to 10.00 s−1. With strain rate decreasing and deformation temperature increasing, dynamic recrystallization (DRX) was promoted in both alloys. The nucleation mechanism of DRX involved grain boundary bulging and subgrain rotation. In case of deformation at low temperatures and high strain rates, the boron-free alloy only showed dynamic recovery (DRV) phenomenon. However, due to the particle-stimulated nucleation mechanism of recrystallization by TiB particles, the boron-containing alloy shows DRX at that condition. These DRX grain nuclei are formed by lattice rotation and subgrain growth from deformation zone in the initial grains, which are close to those of TiB particle. Moreover, the flow stress of the boron-containing alloy is lower than that of the boron-free alloy due to the grain refinement during hot deformation process.