GOALI: Freeze-form Extrusion Fabrication of Composite Structures Using Ultra High Temperature Ceramics and Refractory Metals

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The research objective of this Grant Opportunity for Academic Liaison with Industry (GOALI) project is to apply and integrate theories in mechanical engineering and materials science to the Freeze-form Extrusion Fabrication process for fabrication of graded composite structures. Missouri University of Science and Technology in partnership with Boeing will research the science and technology of using this novel additive manufacturing process to fabricate graded composite structures having controllable gradients between zirconium carbide (an ultra-high temperature ceramic) and tungsten (a refractory metal). Multiple colloidal pastes will be made from combinations of different raw materials (zirconium oxide, carbon, tungsten, carbon and tungsten carbide), and they will be extruded by multiple extruders in varying ratios, simultaneously and continuously, to produce components containing a graded zirconium carbide/tungsten architecture as designed after reaction sintering. The research will focus on understanding rheology and surface chemistry for development of high solids loading and well dispersed colloidal pastes; modeling, analysis and control of the freeform fabrication process; and evaluation of the dimensional accuracy, mechanical properties and microstructure of the fabricated parts after post-processing.This project is expected to generate scientific and technical knowledge on the Freeze-form Extrusion Fabrication process for fabricating graded composite structures. This knowledge will be useful to other extrusion-based freeform fabrication processes. The developed technology will enable tool-less fabrication of 3D components with functionally graded materials, thereby increasing material flexibility and reducing manufacturing costs and times for low-volume components that have complex geometry and demand high performance.