Dynamic Recrystallization Behavior of Ti22Al25Nb Alloy during Hot Isothermal Deformation

Dynamic recrystallization (DRX) of Ti22Al25Nb alloy has been investigated based on the analysis of hot compression experimental data in this paper. The true stress-strain curves of Ti22Al25Nb can be divided into two types: the single-peak conventional dynamic recrystallization (CDRX) curves and the multi-peak discontinuous dynamic recrystallization (DDRX) curves. The multipeak curves indicate the alternate dominance of hardening mechanism and softening mechanism. A critical Zener-Hollomon parameter ln Z(C) has been proposed to divide CDRX from DDRX. The hardening rate and DRX volume fraction of CDRX and DDRX have been analyzed. In addition, the effect of the second-phase particle on the DRX has been studied. DRX process was enhanced by the second-phase particles, but the growth process of recrystallized grains was restrained.