Lasers create ceramics for spacecraft and nuclear reactors in a jiffy

Spacecraft and nuclear reactors rely on ceramics that can withstand temperatures above 2,000 °C. But the traditional process to make these specialty ceramics requires heating the raw materials in a furnace, burning time and energy.

Researchers have now made an ultra-high-temperature ceramic (UHTC) in minutes by blasting its liquid precursor with a laser (J. Am. Ceram. Soc. 2025, DOI: 10.1111/jace.20650). The process could be used to add ceramic coatings to carbon composites or to 3D print complex ceramic structures.

Shaping UHTCs into, say, the dome-like heat shield at the front of a missile is difficult because the ceramics are brittle, says Cheryl Xu, a mechanical and aerospace engineer at North Carolina State University. To easily make such objects, researchers have been trying to use lasers to melt and fuse powders of UHTC materials such as metal carbides.

Xu, Tiegang Fang, and their colleagues start with a liquid precursor of hafnium carbide (HfC). One of the most heat-resistant ceramics, HfC has a melting point of almost 4,000 °C and could be used in extreme applications in aerospace and energy, including hypersonic airplanes. They place the precursor in an inert argon-filled chamber and hit it with 120 W laser pulses. The precursor reaches 2,000 °C within seconds and cross-links to form a solid polymer. Then the organic content decomposes and escapes as gas, leaving the HfC to crystallize and fuse into a dense ceramic.

The mass and volume changes during this conversion process can reduce the strength of the resulting ceramics, says David Lipke, a materials scientist and engineer at Missouri University of Science and Technology who was not involved in the work. He’s curious about the composition and properties of this laser-created HfC ceramic, he says, and would like to see the technique applied to other ceramics with lower-cost precursors. “This would not be a cost-effective method for bulk production, though it might be interesting for coatings,” he says.

For now, the researchers coated a 2.5 × 2.5 cm piece of carbon composite with the precursor and used the laser to form a HfC coating. Xu says they plan to make larger samples and test their mechanical properties next.