Reaction bonded silicon nitride RBSN properties

The ceramic materials investigated in this paper are hot-pressed silicon nitride (HPSN), reaction-bonded silicon nitride (RBSN), zirconia-toughened alumina (AI2O3), and porous SiC. The available material properties for these ceramics are given in Table 4.3. The HPSN and zirconia-toughened alumina ceramics were in the shape of flexural strength test bars cut from billets. The RBSN ceramic was molded into bars of the shape of flexural test specimens. The porous SiC ceramic was provided in the shape of flexural test specimens. 

Table 15.1 Values of the thermal shock resistance parameters R, R, R"" for a range of ceramic materials where HPSN is hot pressed silicon nitride and RBSN is reaction bonded silicon nitride (reprinted from Table 11.1 on p 213 of Ceramics Mechanical Properties, Failure Behaviour, Materials Selection by Munz and Fett, 1999, published with permission from Springer-Verlag GmbFI)...

Since the 1970s, the search for improved materials has led to a better understanding of the role of additives in the densification and microstructural development of silicon nitride-based ceramics and the consequences for final properties [1, 6]. Improvements in powder manufacture and forming techniques and the development of alternative firing processes has led to a complete family of materials including RBSN, HPSN, sintered silicon nitride (SSN), sintered reaction-bonded silicon nitride (SRBSN), gas-pressure sintered silicon nitride (GPSSN), hot isostatically pressed silicon nitride (HIPSN) and silicon nitride alloys or solid solutions termed SiAlONs, based on their elemental components. 

---