November 8-12, 2015
Additive manufacturing (AM) methods have greatly increased our ability to fabricate complex shapes and multi-material, hybrid architectures. However, better materials are needed which compete with conventional engineering materials and fully leverage the unique capabilities of 3D printing. Specifically, lightweight 3D-printable polymer composite materials are of considerable interest, as are new composites which incorporate hierarchical design aspects observed in natural materials, for example, bone, nacre, and wood.
This talk will focus on recent efforts in the development and characterization of epoxy-based 3D-printable composites for use with direct-write additive manufacturing. In this process, visco-elastic inks are deposited via extrusion through small nozzles to fabricate parts layer-by-layer. Because the shear and extensional flows in the nozzle induce alignment of high aspect ratio particles in the ink, highly efficient short fiber composites with exceptional properties can be printed. Furthermore, anisotropy can be tuned in these materials through choice of filler particle morphology, and orientation can be locally controlled within a component by tailoring the print path. Printed, short fiber polymer composites exhibit Young’s modulus values of up to 24 GPa, up to 20x higher than commercially available printed polymers, while maintaining comparable tensile strength values (40-100 MPa). The talk will conclude with mechanical characterization of 3D-printed lightweight cellular structures, as well as initial efforts in printing additional bio-inspired architectures (e.g. brick-and-mortar architecture) and in applying these fabrication routes and printed architectures to other engineering material systems.
Brett Compton, "3D printing of composites with controlled architecture" in "Composites at Lake Louise (CALL 2015)", Dr. Jim Smay, Oklahoma State University, USA Eds, ECI Symposium Series, (2016). http://dc.engconfintl.org/composites_all/37