JI Wenyi, WEI Chuncheng, WANG Weiwei, ZHANG Lulu, LI Sujuan
((School of Materials Science and Engineering, Shandong University of Technology, Zibo 255049, Shandong, China)

Abstract: Laminated ZrB₂-SiCn/Cg ultra-high temperature ceramics were prepared by tape-casting and hot-pressing with nano-SiC powders. Compared with the monolithic ZrB₂-SiCn ceramic prepared by hot press sintering (flexural strength and fracture toughness were 50 MPa and 2.7 MPa·m^1/2, respectively), the laminated ZrB₂-SiCn/Cg ceramics were effectively prevented from cracking by the addition of graphite interface layers. The flexural strength and fracture toughness of the prepared laminated ZrB₂-SiCn/Cg ceramics were 390 MPa and 11.67 MPa·m^1/2, respectively, and the fracture toughness was improved significantly. The laminated ZrB₂-SiCn/Cg ultra-high temperature ceramics are excellent in performance, which is attributed to the absorption of internal stress by the graphite interface layer which at the same time can inhibit the abnormal growth of SiC particles.

Key words: laminated ZrB₂-SiCn/Cg ceramic; graphite; tape-casting; sintering performance; fracture toughness