Microstructures and Properties of B4C-Based Composites with Laminar Structure

Three kinds of ceramic composites with laminar structure, B4C-B4C/Ti3SiC2, B4C-B4C/Ti2AlC and B4C-B4C/8%Si were synthesized by hot pressing sintering, respectively. The microstructures and properties of the composites were investigated in detail. The experimental results showed the two layers of each composite were in good combination and no spallation phenomenon was observed during the process of fracture. The fracture mechanism of three kinds of composites was similar with each other. The fracture mode of ceramic layers was mainly transgranular fracture. The ductile layers which showed good ductile fracture characteristic exhibited a mixed mode of intergranular and transgranular fracture. The results of mechanical properties showed the comprehensive performance of B4C-B4C/8%Si was the best, the flexural strength and fracture toughness of which were 524 MPa and 3.5 MPa∙m1/2 respectively.