Silicon Nitride - Reaction Bonded Rod - Material Information

Reaction Bonded Silicon Nitride (RBSN) is a lightweight, high-strength ceramic engineered for applications requiring superior thermal stability and oxidation resistance. Produced by the nitridation of compacted silicon powder, RBSN offers excellent dimensional control, making it ideal for precision-engineered components such as bearings, seals, and high-temperature structural parts.

Material Overview

RBSN is characterized by a dense microstructure composed primarily of interlocking ?-Si₃N₄ grains. It possesses a density between 2.9 and 3.2 g/cm³, a flexural strength up to 350 MPa at room temperature, and high hardness exceeding 13 GPa (Perevislov, 2021). The reaction bonding process—nitridation of silicon at 1350–1400 °C followed by sintering at up to 1900 °C—creates elongated grains that improve toughness and resistance to thermal shock. Although RBSN is less strong than hot-pressed Si₃N₄, its strength retention up to 1400 °C and oxidation resistance to 1150 °C make it one of the most cost-effective advanced ceramics (Li et al., 2017). Aluminum and silicon additives can be used to tailor microstructure and enhance both thermal conductivity and oxidation resistance (Kusano et al., 2014).

Applications and Advantages

RBSN’s unique combination of thermal, mechanical, and chemical stability allows it to perform reliably in high-stress environments. It is used in turbine components, engine parts, heat exchangers, and wear-resistant bearings. In the automotive sector, porous RBSN has been developed for diesel particulate filter (DPF) substrates due to its high porosity (~50%), excellent oxidation stability, and resistance to CeO₂ ash corrosion (Miyakawa et al., 2003). Sintered RBSN variants also show low degradation in strength above 1200 °C and stable fracture behavior, confirming their suitability for long-term high-temperature service (Yao et al., 2018). These properties, combined with machinability after sintering, make RBSN a versatile and cost-efficient ceramic solution.

Goodfellow Availability

Goodfellow supplies reaction-bonded silicon nitride rods in research and industrial grades, suitable for high-temperature and oxidation-resistant applications. Custom dimensions and material specifications are available upon request. Explore silicon nitride and related advanced ceramics through the Goodfellow product finder.

References

• Li, W., Wu, Y., Huang, R., Ye, S., & Lin, H.-T. (2017). Effect of Si addition on the mechanical and thermal properties of sintered reaction bonded silicon nitride. Journal of the European Ceramic Society, 37(15), 4771–4778. https://doi.org/10.1016/J.JEURCERAMSOC.2017.06.029
• Kusano, D., Hyuga, H., Zhou, Y., & Hirao, K. (2014). Effect of aluminum content on mechanical properties and thermal conductivities of sintered reaction-bonded silicon nitride. International Journal of Applied Ceramic Technology, 11(3), 395–402. https://doi.org/10.1111/IJAC.12035
• Miyakawa, N., Sato, H., Maeno, H., & Takahashi, H. (2003). Characteristics of reaction-bonded porous silicon nitride honeycomb for DPF substrate. JSAE Review, 24(3), 315–321. https://doi.org/10.1016/S0389-4304(03)00050-X
• Yao, D., Chen, H., Zuo, K., Xia, Y., Yin, J., Liang, H., & Zeng, Y.-P. (2018). High temperature mechanical properties of porous Si₃N₄ prepared via SRBSN. Ceramics International, 44(12), 13824–13830. https://doi.org/10.1016/J.CERAMINT.2018.03.044
• Perevislov, S. N. (2021). Sintering behavior and properties of reaction-bonded silicon nitride. Russian Journal of Applied Chemistry, 94(2), 270–277. https://doi.org/10.1134/S1070427221020038