Low temperature processing and properties of porous frit-bonded SiC ceramics

Abstract

Porous frit-bonded SiC ceramics were successfully prepared at a temperature as low as 800°C from SiC, frit, and microbeads (glass or polymer). The effects of SiC starting particle size and microbead addition on microstructure, porosity, and flexural strength were investigated. The addition of hollow glass microbead improved the strength of frit-bonded SiC ceramics without the loss of porosity by acting additional binder phase between SiC grains. The 65 μrn-sized SiC resulted in lower porosity and higher strength than 50 (μn-sized SiC) because of higher packing density. Typical flexural strengths of frit-bonded SiC were 23 MPa at 46% porosity and 19 MPa at 49% porosity.