(2) Inorganic binder strengthening
Ceramic preforms can be strengthened by inorganic binders (water glass and silica sol). The debinding ceramic preforms are dipped with 0.75% (SiO2) (mass fraction) water glass and then calcined at 800 °C. The strength of ceramic preforms reaches 3.9 MPa and thermal properties are not affected [29]. Polycarbosilane (PCS) is another effective inorganic binder and it is converted to SiC whisker. The composites are reinforced hybridly by SiCp and SiCw and the CTE decreases from 7.0×10−6 to 5.4×10−6 K−1 [9].