Boron Carbide - Hot-pressed (B4C) - Material Information

Boron carbide (B?C) is an ultra-hard ceramic material known for its exceptional strength-to-weight ratio, high wear resistance, and outstanding neutron absorption characteristics. After diamond and cubic boron nitride, it is among the hardest materials available. Hot-pressed B?C finds wide applications in defense, nuclear shielding, and industrial wear-resistant components due to its high hardness and excellent thermal stability.

Material Overview

Hot-pressed B?C exhibits a hardness of approximately 38–42 GPa and a fracture toughness around 4–5 MPa·m^1/2 (Perevislov et al., 2017). Its structure is based on icosahedral boron units linked by C–B–C chains, giving rise to low density (2.52 g/cm³) and exceptional mechanical resilience. Recent studies have demonstrated that decreasing grain size enhances tribological behavior, with fine-grained B?C samples showing wear rates as low as 2.15 × 10?? mm³·N?¹·m?¹ (Zhou et al., 2024). Additions of dopants such as Si or CeB? further improve sinterability and fracture toughness by promoting transgranular fracture and limiting crack propagation (Wu et al., 2012). B?C composites combined with ZrB? or metallic phases also exhibit improved toughness and thermal conductivity, reaching up to 70 W·m⁻¹·K⁻¹ at 100 °C (Chakraborty et al., 2015). These attributes make it ideal for high-stress and high-temperature environments where both strength and reliability are paramount.

Applications and Advantages

Hot-pressed boron carbide’s primary applications include lightweight armor, blasting nozzles, cutting tools, and neutron-absorbing control rods in nuclear reactors. Its low density and high elastic modulus make it especially attractive in aerospace and defense industries. The material’s outstanding chemical inertness also supports use in corrosive chemical environments. The combination of high hardness and low thermal expansion ensures stability under rapid temperature changes, enabling use in ballistic and high-wear systems. Additionally, its high neutron absorption cross-section, attributed to the ¹⁰B isotope, underpins its role in radiation shielding and nuclear containment systems.

Goodfellow Availability

Goodfellow supplies hot-pressed boron carbide in a range of purities and dimensions suitable for demanding research and engineering applications. Materials are processed to ensure uniform microstructure and consistent performance. Explore boron carbide and related ultra-hard ceramics through the Goodfellow product finder.

References

• Zhou, Z., Xia, J., Wang, M., Li, R., & Yuan, T. (2024). Effect of grain size on tribological behavior of hot-pressed boron carbide sliding against alumina balls. International Journal of Applied Ceramic Technology, 21(3), 1–11. https://doi.org/10.1111/ijac.14686
• Chakraborty, S., Debnath, D., Mallick, A. R., & Das, P. K. (2015). Mechanical, tribological, and thermal properties of hot-pressed ZrB?–B?C composite. International Journal of Applied Ceramic Technology, 12(3), 545–553. https://doi.org/10.1111/IJAC.12290
• Perevislov, S. N., Lysenkov, A. S., & Vikhman, S. V. (2017). Effect of Si additions on the microstructure and mechanical properties of hot-pressed B?C. Inorganic Materials, 53(4), 409–415. https://doi.org/10.1134/S0020168517040148
• Wu, K. P., Pu, N. W., Ma, H. L., Chen, R., & Wang, Y. (2012). Mechanical properties and microstructure of boron carbide–cerium boride composite. Advanced Materials Research, 482–484, 1551–1556. https://doi.org/10.4028/WWW.SCIENTIFIC.NET/AMR.482-484.1551