Porous Y₂SiO₅ ceramics with a centrosymmetric structure produced by freeze casting

A novel water-based freeze-casting technique was used to prepare porous yttrium silicate (Y₂SiO₅) ceramics. The formation mechanism of lamellar channels of porous ceramics that were arranged centrosymmetrically along the radial axis is discussed in this study. The effect of solid content on the pore structure, porosity, dielectric properties, and mechanical properties of porous Y₂SiO₅ ceramics were investigated. The increase in solid content reduced the porosity, decreased the pore size, and changed the pore structure. Upon increasing the solid content from 15 vol% to 30 vol%, the compressive strength and dielectric constant of the porous Y₂SiO₅ ceramics increased from 1.87 to 8.42 MPa and from 1.86 to 2.85, respectively. Porous Y₂SiO₅ ceramics with these properties can be used in ultra-high temperature broadband radome structures.