Freeze-form Extrusion Fabrication of Functionally Graded Materials

Presented in this paper is a novel additive manufacturing technology for making three-dimensional parts with functionally graded materials (FGMs), called Freeze-form Extrusion Fabrication (FEF). The system development included extruder modeling and control, composition gradient control for a tripleextruder mechanism, and motion code generation for a 3-axis positioning system. The effectiveness of the developed FEF system was demonstrated first by fabricating alumina parts in complex geometries using a tool path planning software and then by fabricating limestone parts with graded colors. Composition verification was then conducted by building ‘green’ parts with graded compositions between alumina and zirconia. The fabricated part went through post-processing and was analyzed using energy dispersive spectroscopy (EDS) to determine its material compositions.