Abstract
This paper investigates the formulation, chemo-rheological properties, and extrusion deposition additive manufacturing (AM) of high glass transition temperature epoxies. Currently there are two methods of using thermoset materials in extrusion deposition AM. The first approach uses a reactive material that will fully cross-link during the build process. The second approach, which is explored in this paper, uses a reactive material that requires a thermal curing cycle after deposition is completed. Yield stress fluids for successful deposition were produced by blending various ratios of rheology modifying fillers into latent curing epoxy systems. After analyzing the rheological properties of the various blends via shear, temperature, and cure rate, the preferred formulation was selected. Test specimens for flexural analysis and dynamic mechanical analysis were printed from down selected combinations. This work resulted in the identification of key parameters for printing latent cured epoxy systems that will be scaled for the first large scale 3D printed epoxy for composite tooling applications.
