Preparation and microstructure of porous ZrB₂ ceramics using reactive spark plasma sintering method

Abstract

Zirconium oxide (ZrO₂) and boron carbide (B₄C) were added to ZrB₂ raw powders to prepare ZrB₂ porous ceramics by reactive spark plasma sintering (RSPS). The reactions between ZrO₂ and B₄C which produce ZrB₂ and gas (such as CO and B₂O₃) result in pore formation. X-Ray Diffraction results indicated that the products phase was ZrB₂ and the reaction was completed after the RSPS process. The porosity could be controlled by changing the ratio of synthesized ZrB₂ to raw ZrB₂ powders. The porosity of porous ceramics with 20 wt% and 40 wt% synthsized ZrB₂ are 0.185 and 0.222, respectivly. And dense ZrB₂-SiC ceramic with a porosity of 0.057 was prepared under the same conditions for comparison. The pores were homogeneously distributed within the microstructure of the porous ceramics. The results indicate a promising method for preparing porous ZrB₂-based ceramics.

Keywords

zirconium diboride / porous ceramic / reactive spark plasma sintering

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