Direct ink writing of high-performance multi-level interlocked laminate-network titanium matrix composites

In this study, multi-level laminate-network boron nitride nanosheets (BNNSs)/TC4 composite with interlayer interlocking was fabricated using a facile direct ink writing (DIW) technique. In-situ 3D nano-configurations consisting of BNNSs and TiBx nanophases distributed around TC4 matrix particles formed the first-level network structure, while the above composite layers and TC4 layers with interlayer interlocking formed the second-level laminate structure. It exhibits a comparable high tensile strength of around 1203 MPa, compared to composites with a single-network structure, while demonstrating a 20% higher toughness of 55.8 MJ/m(3). The interlayer interlocking microstructure interlayer could be responsible for the strength enhancement, which benefits the stress transfer between layers. The improved ductility could be attributed to the crack blocking adduced by the laminate structure and the 3D network in the composite layers.