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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.
Ceramics are much more difficult to process than polymers or metals because they cannot be cast or machined easily. Traditionally, ceramic parts are consolidated from powders by sintering, which introduces porosity and limits both achievable shapes and final strength.
Unlike polymers and some metals, ceramic particles don't fuse together when heated, so the few 3D printing techniques so far developed for ceramics have slow production rates and involve additives that increase the material's tendency to crack.
Dr. Tobias Schaedler, program manager at HRL Laboratories, said: "With our new 3D printing process we can take full advantage of the many desirable properties of this silicon oxycarbide ceramic, including high hardness, strength and temperature capability as well as resistance to abrasion and corrosion.”
The resin contains silicon- and oxygen-based polymers that, upon polymerization, trap the UV light so that additives are not required for the UV curing steps. Once the polymer is printed, the part is heated to a high temperature to burn off the oxygen atoms, forming a highly dense and strong silicon carbide product. The researchers used electron microscopy to analyse the end product, the researchers detected no porosity or surface cracks.
HRL is a corporate R&D laboratory owned by Boeing and General Motors. The research work by HRL’s Senior Chemical Engineer Zak Eckel and Senior Chemist Dr. Chaoyin Zhou is titled "Additive Manufacturing of Polymer Derived Ceramics," and is published in this month's issue of Science.