Fracture behavior of a composite composed by Ti-aluminide multi-layered and continuous-SiCf-reinforced Ti-matrix

In the present work, a novel hybrid composite composed of Ti-aluminide multi-layered part and continuous-SiCf-reinforced Ti-matrix part using a vacuum hot pressing/hot isostatic pressure (VHP/HIP) sintering process was synthesized. Then, the damage tolerance behavior of this hybrid composite was studied by tensile tests and in situ scanning electron microscopy (SEM) three-point bending tests. The results indicate that the mechanical properties and crack propagation of the hybrid composite are strongly influenced by the extrinsic toughness mechanism. In detail, the crack deflection of multi-layered composite and strengthening effect of SiCf-reinforced matrix composite are observed in the hybrid composite. Owing to the strengthening effect of continuous-SiCf-reinforced Ti-matrix part, the tensile strength of hybrid composite is much higher than that of neat Ti-aluminide multi-layered composite. Furthermore, it is found that the optimal damage tolerance ability is optimized when the notch position is located at the Ti-aluminide multi-layered part due to the crack deflection of multi-layered structure.