Silicon Carbide - Hot-pressed (SiC) - Material Information

Hot-pressed Silicon Carbide (SiC) is a high-density, ultra-hard ceramic material valued for its exceptional thermal stability, mechanical strength, and electrical resistance. Once used primarily in refractory linings, modern SiC has evolved into a cornerstone material for advanced engineering and space applications due to its combination of strength, stiffness, and low thermal expansion.

Material Overview

Silicon Carbide (SiC) is a covalently bonded compound of silicon and carbon that can exist in over 200 polytypes, most notably the 4H, 6H, and 3C structures. In its hot-pressed form, SiC achieves near-theoretical density through sintering under high temperature and pressure, resulting in superior hardness (24–27 GPa) and flexural strength (800–1100 MPa). The material also demonstrates excellent thermal conductivity (? 80 W/m·K) and high fracture toughness (5–7 MPa·m^1/2), with electrical resistivity tunable through doping (Yeom et al., 2015; Lee et al., 2005). These characteristics are underpinned by strong Si–C bonds and a stable hexagonal lattice that resists deformation under thermal or mechanical load.

Applications and Advantages

Hot-pressed SiC is employed in environments requiring extreme wear resistance and thermal stability, such as semiconductor processing equipment, mechanical seals, ballistic armor, and optical mirrors for space telescopes. Its high stiffness-to-weight ratio and low coefficient of thermal expansion make it an ideal substitute for glass in lightweight reflective systems. Advances in electrical conductivity control have also opened new possibilities for SiC in power electronics and heating elements (Lim et al., 2014). Furthermore, composites of SiC with Si₃N₄ have been shown to enhance fracture toughness and reduce resistivity, further broadening its engineering versatility (Yeom et al., 2015).

Goodfellow Availability

Goodfellow offers hot-pressed Silicon Carbide in multiple research and industrial formats, including granules and sputtering targets. Each product is manufactured to meet stringent purity and density specifications, with the option for custom dimensions and configurations. For more information on available forms, visit the Goodfellow product finder.

Explore Silicon Carbide and other advanced materials in Goodfellow’s online catalogue: Goodfellow product finder.

References

• Yeom, H.-J., Kim, Y.-W., & Kim, K. J. (2015). *Electrical, thermal and mechanical properties of silicon carbide–silicon nitride composites sintered with yttria and scandia*. Journal of the European Ceramic Society, 35(2), 587–594.
• Lee, S.-H., Lee, Y. I., Kim, Y.-W., Xie, R.-J., Mitomo, M., & Zhan, G. (2005). *Mechanical properties of hot-forged silicon carbide ceramics*. Scripta Materialia, 52(1), 57–61.
• Lim, K.-Y., Kim, Y.-W., & Kim, K. J. (2014). *Mechanical properties of electrically conductive silicon carbide ceramics*. Ceramics International, 40(8), 12733–12738.
• Kimoto, T., & Cooper, J. A. (2014). *Physical properties of silicon carbide*. In *Silicon Carbide Power Devices* (pp. 45–78). Wiley.