A novel configuration design of strong and ductile (TiC+Ti5Si3)/Ti laminated composites

To solve the low ductility of the uniformly particle-reinforced composites, novel (TiC + Ti5Si3)/Ti laminated composites are fabricated by electrophoretic deposition (EPD) silicon (Si) powders + graphene oxide (GOs) and spark plasma sintering (SPS) technology. The microstructure evolution, mechanical properties, strengthening and fracture mechanisms of laminated composites were systematically studied. Results show that the GOs and Si powders are evenly attached to Ti foils after EPD, and the (TiC + Ti5Si3) reinforcements are in situ formed at the interface after SPS. TiC phases are distributed along the original interface, and most of the Ti5Si3 reinforcements are located in the Ti foil matrix. The 50 mu m - 120 s sample possesses obvious shell nacre containing particular "brick-and-mortar" architecture structure. And the 100 mu m - 120 s sample displays excellent room temperature tensile properties, with the ultimate tensile strength (UTS) of 759 MPa, yield strength (YS) of 688 MPa and elongation (EL) of 24.3 %. The change of microstructure leads to the increase of strength, which is caused by the solid-solution strengthening, grain boundary strengthening and reinforcements strengthening. At this time, the design of laminated structure can change the crack propagation direction, extend the crack propagation path and thereby increases the energy required for crack propagation, obstructing the fracture of composites. This work provides an effective method to prepare Ti matrix composites with synergy of strength and ductility.