Breakthrough in Si3N4 Ceramics Enhances Aircraft Performance - TUN

The University Network

A pioneering team of material scientists led by Zhilin Tian and Bin Li from Sun Yat-sen University in China has revealed a groundbreaking advancement in the development of porous Si3N4 ceramics. Using a novel dual-solvent templating and freeze-casting method, the researchers have managed to significantly enhance the dielectric, mechanical and thermal properties of Si3N4 ceramics, promising transformative implications for aerospace technology.

Si3N4 ceramics are considered one of the most promising materials for high-performance aircraft components, such as radomes and wave-transmitting antenna windows. These materials protect radar antennas from external interference while ensuring reliable communication, a critical function in hypersonic vehicles. However, traditional Si3N4 ceramics often struggled to balance mechanical strength with wave transmission efficiency.

Tian, an associate professor in the School of Materials Science at Sun Yat-sen University, highlighted the importance of their innovation.

“In this study, we developed porous Si3N4 ceramics with uniform pore structures using a dual-solvent templating and freeze-casting method. The resulting ceramics have a porosity of 56% and exhibit impressive mechanical properties, with bending and compressive strengths of 95±14.8 MPa and 132±4.5 MPa, respectively,” he said in a news release.

The dual-solvent system, which uses tert-butyl alcohol and camphene, allows precise control over the pore size and structure. This method enables the transformation of anisotropic prismatic pores into isotropic spherical pores, a key factor in improving the material’s properties.

“Our dual-solvent templating method offers unprecedented control over pore size and structure, which are critical for creating high-performance ceramics for aerospace applications,” added Tian.

By adjusting the ratios of the solvents, the team found they could fine-tune the ceramic’s structural characteristics.

“The combination of tert-butyl alcohol and camphene as templates allows us to achieve isotropic spherical pores, greatly enhancing both mechanical strength and thermal properties,” Tian added. “The competition between solvent crystals helps achieve optimal pore size, leading to improved crack deflection and energy absorption under high-speed flight conditions.”

The implications of this discovery are significant. Enhanced Si3N4 ceramics could not only improve the durability and efficiency of radomes and antenna windows but also meet the stringent demands of hypersonic flight. These ceramics need to withstand extreme temperatures and stresses while maintaining low dielectric constants to ensure effective radar functionality.

Published in the Journal of Advanced Ceramics, this research sets the stage for further advancements. Tian and his team are now focused on scaling up the production process and refining the material’s properties for various aerospace applications.

“Our ultimate goal is to develop a class of ceramics that can be utilized in a wide range of extreme environments,” Tian added.