Densification mechanism and corrosion resistance of h-BN/ZrO2 ceramics prepared by spark plasma sintering

The dense h-BN/ZrO2(30 wt%) composites without additives were rapidly fabricated by spark plasma sintering. The relative density, apparent porosity, fracture toughness, flexural strength, phase composition and microstructure of h-BN/ZrO2 composites were systematically investigated. Besides, the corrosion resistance of h-BN/ ZrO2 composites in molten steel was also studied in detail. Especially, the h-BN/ZrO2 composites were sintered at 1800 degrees C exhibiting a relative density of 96.6% and the flexural strength of approximate to 157 MPa. The corrosion of h-BN/ ZrO2 composites was mainly due to the oxidative decomposition of BN, and the corrosion process was clarified by a parabolic law. The excellent corrosion resistance of the h-BN/ZrO2 composites was attributed to ZrO2 residual layer formed at the interface. The corrosion thickness of h-BN/ZrO2 composites was only similar to 116 mu m even using the longest corrosion time (80 min). The composites could be a promising candidate material applied to fabricated thin strip continuous casting side sealing plates.

Automated summary

Dense h-BN/ZrO2(30 wt%) composites were fabricated by spark plasma sintering without additives. The composites were characterized for their relative density, apparent porosity, fracture toughness, flexural strength, phase composition, and microstructure. Furthermore, the corrosion resistance of the composites in molten steel was investigated, with the results showing excellent corrosion resistance attributed to the ZrO2 residual layer at the interface. The composites exhibited potential for application in fabricating thin strip continuous casting side sealing plates.