In situ foam-gelcasting fabrication and properties of highly porous γ-Y2Si2O7 ceramic with multiple pore structures

Highly porous gamma-Y2Si2O7 is fabricated by the in situ foam-gelcasting reaction sintering method using Y2O3 and SiO2 starting powders. The prepared porous gamma-Y2Si2O7 has multiple pore structures, including interconnected large pores and small pores in the skeleton. The sample sintered at 1550 degrees C has low linear shrinkage (6.0%), high porosity (84.9%), high compressive strength (6.22 MPa), and low thermal conductivity (0.230 W/(m K)). This work sheds light on porous gamma-Y2Si2O7 as a promising high-temperature thermal insulator. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.