Interfacial structure and mechanical properties of laminated composites of TiB₂ based ceramic-42CrMo alloy steel

The laminated composites of TiB₂ based ceramic-42CrMo alloy steel were rapidly prepared by self-propagating high-temperature synthesis centrifugal-casting process, and the span-scale continuously-graded composite structures of three dimensional-network TiB₂ matrix ceramic/Fe-Ni alloy developed on the interface between the layers, leading to the laminated composite with 3-layer structure consisting of ceramic matrix, the intermediate and alloy steel matrix. Combining mechanical properties test with FESEM and HETEM examination, it is considered that the in-situ achievement of the continuously-graded composite structure of three dimensional-network span-scale TiB₂ matrix ceramic/Fe-Ni alloy in interlaminar interface not only presents the laminated composite with high flexural strength and high fracture toughness, but also presents the composite with the mechanic behavior of bogus plasticity when the three point bending test conducts. Meanwhile, the cooperative action of crack interlocking by TiB₂ matrix ceramic/Fe-Ni based alloy composite structure nearby the ceramic matrix with precipitation strengthening by micro-nanometer or nanometer TiB₂ platelets in the intermediate also presents the laminated composite of TiB₂ based ceramic-42CrMo alloy steel with high interlaminar shear strength.