Researchers in the US have developed a ceramic resin that enables the 3D printing of higher strength, higher temperature components suitable for applications in jet engines, microelectromechanical systems and possibly hypersonic vehicles.
The resin, which has been developed at HRL Laboratories, can be 3D printed into parts of virtually any shape and size, enabling complex, curved and porous ceramic components. The printed resin can then be fired, converting it into a high strength, fully dense ceramic.
The resulting material can withstand ultrahigh temperatures in excess of 1700°C and exhibits strength ten times higher than similar materials.
Previously, The extremely high melting point of many ceramics adds challenges to additive manufacturing as compared with metals and polymers. But now, the invented preceramic monomers are cured with ultraviolet light in a stereolithography 3D printer forming 3D polymer structures that can have complex shape and cellular architecture. These polymer structures can be pyrolyzed to a ceramic with uniform shrinkage and virtually no porosity by heating. The used silicon oxycarbide microlattice and honeycomb cellular materials fabricated with this approach exhibit higher strength than ceramic foams of similar density.
Additive manufacturing of such materials is of interest for propulsion components, thermal protection systems, porous burners, microelectromechanical systems, and other applications.
Polymer-derived ceramics were discovered in the 1960s. upon heat treatment (typically under inert atmosphere), they pyrolyze into SiC, Si3N4, BN, AlN, SiOC, SiCN, BCN, or other compositions, whereas volatile species (CH4, H2, CO2, H2O, and hydrocarbons) leave the material. By attaching thiol, vinyl, acrylate, methacrylate, or epoxy groups to an inorganic backbone such as a siloxane, silazane, or carbosilane, ultraviolet (UV)–active pre-ceramic monomers can be obtained.
Eng. Rami Khalil
Mechanical Design and Production Engineer.