Aqueous gelcasting and pressureless sintering of zirconium diboride foams

Direct foaming technique was utilized to fabricate high-performance ZrB2 porous ceramics. 45 vol% ZrB2(–B4C) slurries were prepared, together with polyacrylate dispersant and foaming agent. After gelcasting and pressureless sintering, porous ZrB2 ceramics were obtained. Thanks to the good fluidity and the presence of 2 wt% B4C as the sintering aid, Z-2B ceramic of dense strut and porous structures (55% in porosity) was obtained. Its compressive strength was 79.8±8.7 MPa. The co-relations between microstructures and mechanical properties of the as-prepared ZrB2 cellular ceramics were also studied.