Enhanced Thermal Insulation and Mechanical Strength of Fiberglass Porous Ceramics via Adjustment of the Structure of Pores

Abstract

Fiberglass porous ceramics were prepared via a foam-gelcasting method. The relationship between the rheology of the slurries and the structure of the specimens was investigated. The results show that when the content of the dispersant was 0.25 wt %, the slurries exhibit excellent fluidity. The thixotropic behavior of the slurries was strongly influenced by the content of the foam stabilizer agent and solid content. Furthermore, as the fluidity of the foaming slurries increased, the size of the pores increased. At the same time, the thickness of the pore walls decreased gradually. In addition, promoting the uniform distribution of the pore size by improving the thixotropic behavior of the foaming slurries was beneficial. The optimal foaming slurry was composed of 65 wt % fiberglass, 0.25 wt % dispersant, and 0.1 wt % foam stabilizer agent. After calcination at 750 °C, fiberglass porous ceramics with 78.3% porosity, 2.2 MPa compressive strength, and 0.11 W m–1 K–1 thermal conductivity were obtained.