Precipitation Behavior of Silicide in TiCp/Ti Composites Induced by Hot Deformation During β Phase Region

Thermal physical simulation experiments during beta phase region were carried out on 5%TiCp/near-alpha titanium matrix composites (volume fraction) to investigate the precipitation behavior of silicides and the deformation mechanism of beta phase during the hot deformation of the composite. After deformation, the microstructure is mainly composed of lamellar a phase and broken TiCp at room temperature. The existence of S-2 type (Ti,Zr)(6)Si-3 silicides in the microstructure was confirmed by transmission electron microscopy (TEM). The content of silicides increases with the increasing temperature or decreasing strain rate. In addition, the parent beta grains were reconstructed by a phase at room temperature. TiCp distributes along the beta grain boundary, which promotes the dynamic recrystallization of beta phase by providing nucleation sites and hindering dislocation movement. The high-density dislocations induce and promote the precipitation of silicides caused by accumulation of strain and TiCp during hot deformation.