Materials and process development for direct digital manufacturing of vehicles

Recent developments in large-scale direct digital manufacturing (DDM) technology have led to its integration into manufacturing sectors including the automotive industry. 3D printing technology is enabling the rapid design-to-manufacture of production automotive vehicles, an application that will require the development of: a material property database, an understanding of the effects of print parameters on mechanical properties, new manufacturing techniques for reinforcement of printed structures, and materials tailored for printing. A review of the progress in these four development areas is presented herein. Early efforts include baseline mechanical properties of large-scale printed materials (including carbon fiber-filled acrylonitrile butadiene styrene (CF/ABS)) and the effects of print parameters on those properties. Reinforcement techniques for the printed material include foam-filling, carbon fiber overwrap, and various infill patterns; these multi-material structural elements have been evaluated under torsional loading. New materials development for 3D printing includes nylon and co-polyester reinforced with carbon fibers and graphene nanofillers.