Additive manufacturing of (TiB+TiC)/Ti6Al4V composites with tailored network reinforcement architecture

(TiB + TiC)/Ti6Al4V composites with controllable three-dimensional network structure were fabricated from mixed spherical Ti6Al4V and boron carbide (B4C) powders by laser directed energy deposition (LDED) based additive manufacturing process (AM). The (TiB + TiC) precipitates significantly refined the microstructure and aggregated at prior beta grain boundaries forming network structure. The increase of the B4C content reduced the network size and the tensile performance of the composites was associated with the network size. (TiB + TiC) pinned on the network allowed specific strengthening effect, benefiting the enhancement in tensile strength of the composites, while the network structure together with alpha lamellae size gradient structure contributed to high uniform tensile ductility. This work demonstrates the significant potential of additive manufacturing process in creating a new class of metal matrix composites with tailored three-dimensional architecture.