New multifunctional porous Yb2SiO5 ceramics prepared by freeze casting

New porous Yb2SiO5 ceramics were prepared by a water-based freeze casting technique using synthesized Yb2SiO5 powders. The prepared porous Yb2SiO5 ceramics exhibit multiple pore structures, including lamellar channel pores and small pores, in its skeleton. The effects of the solid content and sintering temperature on the pore structure, porosity, dielectric and mechanical properties of the porous Yb2SiO5 ceramics were investigated. The sample with 20 vol% solids content prepared at 1550 °C exhibited an ultra-low linear shrinkage (i.e. 4.5%), a high porosity (i.e. 79.1%), a high compressive strength (i.e. 4.9 MPa), a low dielectric constant (i.e. 2.38) and low thermal conductivity (i.e. 0.168 W/(m K)). These results indicate that porous Yb2SiO5 ceramics are good candidates for ultra-high temperature broadband radome structures and thermal insulator materials.