High-Temperature Hot Deformation Behavior and Processing Map of TC11 Titanium Alloy

In this study, the high-temperature deformation behavior of TC11 titanium alloy was investigated through hot compression experiments. The relationship between flow stress, strain rate, and deformation temperature was described by analyzing stress–strain curves and establishing a constitutive equation. A hot processing map was constructed based on the Dynamic Materials Model (DMM). The processing map indicated that the optimal processing regions were 1155–1195 K/0.1–8 s−1 and 1265–1273 K/0.1 s−1. EBSD analysis showed that under low-strain-rate conditions, the fraction of high-angle grain boundaries and the proportion of recrystallized grains were relatively high, with dynamic recrystallization primarily governing softening. As the strain rate increased, the proportion of recrystallized grains decreased, the fractions of substructure and deformed grains increased, and dislocation accumulation was significantly enhanced, resulting in a shift in the softening mechanism from dynamic recrystallization to dynamic recovery. Elevated temperatures facilitated dislocation slip and climb, promoting nucleation and growth of dynamic recrystallization, whereas excessively high temperatures caused grain coarsening and localized distortion accumulation, reducing microstructural stability. TEM observations further confirmed that low-strain-rate conditions produced a greater number of recrystallized grains with low dislocation density, while high-strain-rate conditions exhibited pronounced subgrain structures and increased dislocation density. This work constructs the hot processing map of TC11 alloy near β-transus temperature and quantitatively links power-dissipation domains with multi-scale EBSD/TEM microstructure statistics. The obtained hot working window can provide guidance for parameter optimization of high-temperature thermomechanical processing of TC11 aerospace components.