A D V A N C E D M A T E R I A L S & P R O C E S S E S | J U L Y / A U G U S T 2 0 2 1 7 2 3D PRINTSHOP Large-scale mold printed with recycled thermoplastic composite and syntactic foam. BIGGER, YET LIGHTER BUILDS USING RECYCLED MATERIALS Oak Ridge National Laboratory researchers, in collaboration with Cincinnati Inc., demonstrated the potential for using multimaterials and recycled composites in large-scale applications by 3D printing a mold that replicated a single facet of a precast concrete tool. The team added a dual feed system to the Big Area Additive Manufacturing (BAAM) machine, a large format tool developed by ORNL and Cincinnati Inc. This enabled printing with multiple materials in a single build using one extruder. Within seven hours, the large 3D printer produced a 400 lb mold measuring 10 ft in length made of recycled carbon fiber reinforced thermoplastic and syntactic foam. BAAM’s goal is to 3D print large, near-net shape parts as quickly as possible. Large-scale printing with multimaterials and recycled composites is anticipated to lower the cost of tooling and open opportunities for printing structures with lightweight cores and tailored properties. “New mechanical responses can be achieved with multimaterial printing such as soft and rigid segments within a part and impact resistant structures,” says ORNL’s Vidya Kishore. ornl.gov. 3D-PRINTED COMPLEX MICRO-OPTICS Researchers from the University of Stuttgart, Germany, have shown that 3D printing can be used to make highly precise and complex miniature lenses with sizes of just a few microns. The microlenses can be used to correct color distortion during imaging, enabling small and lightweight cameras that can be designed for a variety of applications. “The ability to 3D print complex micro-optics means that they can be fabricated directly onto many different surfaces such as the CCD or CMOS chips used in digital cameras,” says Michael Schmid, a member of the research team. “The micro-optics can also be printed on the end of optical fibers to create very small medical endoscopes with excellent imaging quality.” The study, published in the Optical Society journal, Optics Letters, details how they used a type of 3D printing known as two-photon lithography to create lenses that combine refractive and diffractive surfaces. They also show that combining different materials can improve the optical performance of these lenses. “3D printing of micro-optics has improved drastically over the past few years and offers a design freedom not available from other methods,” says Schmid. “Our optimized approach for 3D printing complexmicro-optics opens many possibilities for creating new and innovative optical designs. osa.org. EB-BASED PRINTING FOR VARIABLE PROPERTIES Dr. Carolin Körner from Friedrich- Alexander-Universität Erlangen-Nürnberg, Germany, has been awarded an Advanced Grant from the European Research Council for her work in additive manufacturing of high-performance components using high-energy electron beams. Electron beam-based additive manufacturing allows voxel-based material design; in other words, the highly precise tuning of local material properties, with the term voxel derived from pixel-based resolution of 2D images. This process makes it possible for various areas within a component to be given different properties. The project, Voxel-Based Material Design: Amalgamation of Additive Manufacturing and Scanning Electron Microscopy, AMELI for short, hopes to open up pioneering new possibilities for component manufacturing. “The groundbreaking combination of local- ly adjustable material properties and freedom of construction shifts the limitations of components made fromhigh-performance alloys,” explains Körner. As a result, additive manu- facturing is becoming increasingly interesting for the aviation industry, and may also be able to contribute to increasing the effectiveness of land- based gas turbines or accelerating the expan- sion of hydrogen produc- tion facilities. www.fau.eu. Researchers used 3D printing to make highly precise and complex apochromatic miniature lenses that can be used to correct color distortion during imaging. Courtesy of Michael Schmid/University of Stuttgart.
RkJQdWJsaXNoZXIy MTYyMzk3NQ==