Hot deformation temperature and pre-deformation effect on silicide precipitation behavior of (TiB+Y2O3)/near α-Ti matrix composite

Based on the hot compression tests, the effects of deformation temperature and pre-deformation on the microstructure evolution of a hybrid (TiB+Y2O3)/near alpha-Ti matrix composite were studied. The results indicate that the size of silicide precipitated increases with increasing deformation temperature, but its quantity increases first and then decreases. Pre-deformation makes the precipitation position of silicide transform from alpha/beta interfaces or beta blocks to uniform distribution inside the matrix. Dynamic recrystallization (DRX) is the main reason for grain refinement of composite, and the dislocations produced by pre-deformation accelerate the process of continuous dynamic recrystallization (CDRX). During the deformation process, dislocations proliferate and aggregate around the broken TiBw and polymerized Y2O3 reinforcements, which promotes the refinement of local grains. Different from the effect of TiBw and Y2O3 on the grain refinement, nano silicides promote the DRX of alpha grains by pinning grain boundaries and blocking the movement of dislocations according to their different distribution positions.