Recently, the U.S. Air Force Research Laboratory, in collaboration with the NASA Glenn Research Center and the University of Louisville, has developed a method for 3D printing of high temperature resistant polymers. The researchers used high-temperature thermosetting resins impregnated with carbon fiber filaments and selective laser sintering processes to successfully print high-temperature-resistant polymer-based composite parts that can withstand temperatures higher than 300°C. They are expected to be used in the future for high temperatures around turbine engine spare parts or engine exhaust. area.
The lightweight properties of polymer-based composites and their ability to withstand high-temperature environments can help increase the range of aircraft while reducing fuel consumption and operating costs, making it attractive for the Air Force's next generation of equipment applications. This disruptive discovery laid the foundation for meeting the Air Force's next-generation, cost-effective manufacturing needs.
In general, polymer-based composites incorporate fibers such as glass fibers into epoxy or other matrix materials. Embedded fibers reinforce the matrix and make the material more robust.
In the process of polymer 3D printing using a laser sintering process, high-temperature laser light is passed through the polymer powder bed to form a computer pre-designed shape. The laser powder is then used to shape the new powder layer and this process is repeated several times until the 3D part is completed.
When testing high-temperature polymer resins, the team found that additive manufacturing techniques printed polymer powders well, but when they removed parts from the powder bed for post-treatment, the materials melted and could not be used.
To solve this problem and better enable the molecules to be wound and shaped under the heat of the laser, the researchers added carbon fiber fillers to the resin material to better transfer the laser energy to the substrate. By absorbing the laser's energy and conducting heat, carbon fiber will cause the laser to heat the material much faster than using the polymer alone.
Researchers say that the processing of high-temperature materials is very difficult and expensive, and this material is usually used for military-specific purposes, and its suppliers have less resources. This breakthrough will enable the U.S. Air Force to manufacture high temperature composite parts in a more cost-effective manner. Moreover, high-temperature polymer composite parts are characterized by small size and multiple functions. The latest research results will not only bring great benefits to the Air Force, but also may bring disruptive impact to the entire industry.
Preliminary testing data shows that this new material can withstand high temperatures, but further testing and verification of the material is required before it is actually applied to the Air Force platform.