Mechanical properties and crack propagation behaviors of laminated Ti/Al2O3 composite

Laminated Ti/Al2O3 composite was fabricated by tape casting and vacuum hot-pressing sintering with intent to research mechanical properties including the fracture strength and toughness. The results showed that the flexural strength and fracture toughness improved according to the amount of layers. When the amount of layers was 35, the flexural strength and fracture toughness reached 361 MPa and 9.72 MPa m1/2, respectively. Based on the observation of microstructures, it was concluded that the improvement of mechanical properties was attributed to various crack propagation (such as crack deflection, crack bifurcation, crack termination and interface dissociation). The characterization of EDX and XRD at interfaces indicated that the initiative diffusion of O2− from Al2O3 to Ti layer led to the passive diffusion of Al3+ (aggregating near the interface) and reacted with Ti to form Ti3Al, Ti[O] and AlTiO2 solid solution.