Impact behavior of in-situ TiB/Ti6Al4V composite with tailored gradient-layered network structure

With the increasing demand for high impact resistance of light metals under the extreme condition in aerospace, an impact resistant TiB/Ti6Al4V titanium matrix composite (TMC) with tailored gradient-layered network structure was newly designed and fabricated by gradiently changing the reinforcement content. Pendulum impact tests were conducted to evaluate its impact behavior. It was found that the energy absorption of gradient-layered TMCs with network structure was four times higher than that of homogeneous TMCs, and much higher than that of the traditional layered TMCs. Microscopic characterization of the crack propagation behavior revealed that several anti-impact mechanisms, such as crack blunting in the soft layers, interfacial crack deflection, secondary cracks and plastic deformation in the strong layer, contributed to the excellent dynamic fracture resistance of gradient-layered TMCs. This work proposes an efficient structure-design strategy for developing high impact resistant TMCs, which is useful to expand the development of other metal matrix composites possessing high strength and impact resistance in aerospace field.