Microstructure evolution and deformation mechanism of precursor-derived (TiB + TiC + Ti₃Si)/TC4 composites

In this study, the in-situ derived (TiB + TiC + Ti₃Si)/TC4 composites were prepared by employing the boron-modified polysilazane polymer as a source of B, C, and Si. The hybrid reinforcements architecture comprises ultralong TiB nanowires and micron-sized spherical TiC particles distributed at grain boundaries, integrated with submicron rod-shaped Ti₃Si particles located at α/β-Ti phase boundaries. The microstructure evolution and hot deformation behavior of these composites were investigated within the temperature range of 900–1020 °C and strain rates of 0.001–1 s⁻¹, focusing on softening mechanisms, dynamic recrystallization (DRX), dynamic recovery (DRV), and the dynamic materials model. The hybrid reinforcements significantly influence dislocation movement and distribution, altering deformation energy dissipation and facilitating DRX and DRV across various thermomechanical conditions. Consequently, the resulting microstructures exhibit substantial grain refinement and equiaxed grains. This work advances understanding of hot deformation mechanisms in titanium matrix composites reinforced with precursor-derived hybrid architectures and supports the development of (TiB + TiC + Ti₃Si)/TC4 composites for broad industrial applications.