Mechanical and thermal shock properties of laminated ZrB2-SiC/SiCw ceramics

Laminated structure is an effective design to improve the fracture and ablation behaviors of ceramics in the high temperature fields. To investigate the effect of interface layer on the fracture manner of laminated ceramics, two laminated ZrB2-SiC/SiCw (LZS(w)) and ZrB2-SiC/SiCp (LZS(p)) ceramics were prepared by hot pressing with SiC whiskers and SiC powders as strong interface layers, respectively. The flexural strength and fracture toughness of LZS(w) ceramic reached 471 MPa and 15.9 MPa m(1/2), respectively. This improved fracture toughness of the LZS(w) ceramic was mainly attributed to the introduction of SiC whiskers as the strong interface layer, which significantly prompted crack deflection and branching, increased crack propagation path and consumed more fracture energy during fracture process.