US breakthrough may speed up production of hypersonic shields and rocket parts

Researchers at Johns Hopkins University Applied Physics Laboratory (APL) have developed a method to significantly accelerate the production of carbon-carbon composites. This advancement could replace the current slow and labor-intensive manufacturing process, reducing production costs.

"The speed of FAST CAR 2 is what makes it so compelling," stated Sal Nimer, Assistant Manager of APL’s Science of Extreme and Multifunctional Materials program. "It has the potential to enable faster and more efficient production of advanced materials for high-performance applications, such as rocket nozzles and hypersonic vehicles," he added.

Carbon-carbon composites consist of carbon fiber embedded in a solid carbon matrix, similar to carbon-fiber reinforced plastic but with carbon instead of epoxy or resin. This composition results in a material that is lightweight, mechanically strong, and highly heat-tolerant, making it suitable for applications like rocket nozzles, re-entry systems, missile nose cones, aircraft brakes, and hypersonic thermal protection.

"Carbon-carbon is crucial for thermal protection systems in high-speed flight vehicles," explained William Fahy, an APL materials engineer and co-leader of the FAST CAR 2 project. "It was essential for the heat shield on NASA’s Parker Solar Probe, the closest spacecraft to the Sun," he noted. However, the current manufacturing process is slow.

Traditionally, a porous carbon-fiber structure is filled with additional carbon through repeated gas deposition or resin soaking and pyrolysis. FAST CAR 2 simplifies and accelerates this by placing a carbon-bearing material directly into the fiber preform and rapidly heating and compressing it using field-assisted sintering.

This technique uses electrical current for rapid heating while applying pressure to densify the material in minutes, though the entire process still takes days. "We aim to change the mechanism itself to achieve faster production," said Chapkin. "The theory was there, but we were uncertain if the material would hold together," he added.

The team is now collaborating with external partners to scale the process using larger presses, which could expand its applications. "Scaling is challenging," Fahy acknowledged, "but the rapid progress and success so far make us optimistic about future developments," he concluded.