Net Shape Composites Using SLA Tetracast Patterns

Net-shape composites have been a focus of Solid Freeform Fabrication (SFF) for a number of years. A new method to achieve net-shape composites uses hollow Stereolithography (SLA) TetraCast* patterns. The TetraCast* pattern is injected with a filler material consisting of a matrix (typically epoxy) and reinforcement fibers, flakes, andlor particles. Upon solidification ofthe injected matrix, the net-shape composite is achieved. Net-shape composites are ideal for custom manufacturing due to the virtually limitless geometry capabilities of SLA. Areas such as aerospace, medical, manufacturing, and others could someday benefit from this process. Research to date has shown this composite structure to follow the "rule ofmixtures." It has also been shown that heat-deflection, elasticmodulus, and tensile-strength can be enhanced andlor predicted in the composite material. Several areas of continuing research include: viscosity limitations, stair-step notch reduction, reinforcement combinations, shrinkage prediction, cooling methods, SLA skin removal, nextgeneration TetraCast* structures, wear-resistant coatings, process automation, and TetraCast* pattern fill methods.