Â鶹ÒùÔº

Ceramic powders with Archimedean shapes resist extreme heat and oxidation

A research team led by Prof. Hu Xiaoye from the Hefei Institutes of Â鶹ÒùÔºical Science of the Chinese Academy of Sciences has synthesized high-quality boride ceramic powders with an Archimedean shape.

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

Boride ceramics are renowned for their high melting points, excellent oxidation resistance, and outstanding corrosion resistance, making them ideal candidates for heat-resistant materials. However, the synthesis of high-performance boride ceramic composites has remained a significant challenge, particularly in producing high-purity powders.

In this study, the researchers refined a precursor-carbon/boron thermal reduction process to successfully produce high-purity ZrB₂ and HfB₂ powders, known for their superior properties. By introducing a novel sol-gel-assisted carbon-boron reduction method, they achieved molecular-level mixing at low temperatures, resulting in high-purity ceramic 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 then 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 in high-temperature environments.

These Archimedean polyhedral-shaped ceramic powders not only improved the material's oxidation resistance but also formed a protective MO₂ layer on the surface when subjected to extreme heat. When exposed to 1,400°C for three hours, the ceramic oxidation layer formed on the surface measured just 86.43 micrometers in thickness, a significant improvement over similar materials reported in previous studies.

This breakthrough in ceramic powder synthesis not only offers a new approach to producing advanced materials but also opens up new avenues for developing ultra-high-temperature materials capable of withstanding extreme conditions.