Ti3AlC2 preceramic paper derived in-situ laminated TiC/Ni-Ni3(Al,Ti) composite: Microstructure, mechanical properties and fracture behavior

In the present study, a biomimetic strategy concerning to surmount the predicament of strength-toughness tradeoff in the Ni matrix composite was carried out. By assembling Ti ₃AlC ₂-based preceramic papers with pure Ni foils alternatively, a novel kind of in-situ TiC/Ni-Ni ₃(Al,Ti) composite with a mimicking nacre architecture was successfully fabricated. The results show that the grain gradient of in-situ TiC combined with γ`-Ni ₃(Al,Ti) was generated in the composite layer and alloy layer, respectively. The interlayer interface was well-bonded without microvoids, flaws, or other defects. Ascribed to an excellent combination of hard-soft laminate architecture, grain gradient as well as superior interfacial bonding, a synergy of mechanical strength and toughness in the laminated TiC/Ni-Ni ₃(Al,Ti) composites was achieved. The Vickers hardness increases gradually along alloy layer, interface, and composite layer. The flexural strength and fracture toughness were ∼18 % and ∼92 % higher than the counterpart of homogeneous TiC/Ni-Ni ₃(Al,Ti) composite. The laminated architecture enhances the efficiencies of gradient TiC grains in mechanical strengthening for required bearing and loading transmission, and toughens composite materials by interfacial delamination, cracks deflection, bridging and blunting.