Researchers create high-performance ceramic powders with Archimedean shapes for next-gen heat shields

A research team led by Prof. HU Xiaoye from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, has successfully synthesized high-quality boride ceramic powders with an Archimedean shape.

These findings, published in the Journal of the European Ceramic Society, hold promising implications for the future of heat protection materials.

Boride ceramics, known for their extremely high melting points, excellent oxidation resistance, and outstanding corrosion resistance, are considered ideal candidates for heat shields in extreme environments. However, creating high-performance boride ceramic composites requires the synthesis of top-quality ceramic powders, and achieving this has always been a challenging task.

In this study, the team refined a method involving precursor-carbon/boron thermal reduction processes, successfully producing high-purity ceramic powders, such as ZrB₂ and HfB₂, which are known for their superior properties.

Using a novel sol-gel-assisted carbon-boron reduction method, the researchers achieved molecular-level mixing at low temperatures, resulting in high-purity ZrB₂ and HfB₂ powders. By adding dispersing agents like polyethylene glycol (PEG) and oleic acid, they managed to reduce the particle size and prevent aggregation, offering precise control over the ceramic powder's dimensions. 

They created boride powders with Archimedean polyhedral shapes—complex, highly symmetrical geometries that enhance the mechanical and electrical properties of the ceramics. These new powders have exceptional crystallinity, reducing defects and improving the material's overall performance. The high crystallinity of the polyhedral morphology also prevents weakening at grain boundaries, reducing the risk of oxidation and improving the material’s longevity at high temperatures.

These Archimedean polyhedral-shaped ceramic powders not only improved the material' s oxidation resistance but also formed a protective M0₂ layer on the surface when subjected to extreme heat. When tested under 1400°C for 3 hours, the ceramic oxidation layer was only 86.43 micrometers thick—significantly better than similar materials reported in existing literature.

This breakthrough not only offers a new way to prepare ceramic powders but also opens up new possibilities for developing ultra-high-temperature materials that can withstand the extreme conditions.