Abstract
Polymer-metal composite feedstocks have been designed to be adapted for the fused filament fabrication process. These composites are complex fluids when melted and therefore have intricate behaviors during processing. Other research and production of such materials have mainly been limited to steels, whereas in this work, biomedical metal such as magnesium and titanium are studied. Previous work has only focused on creating feedstock filaments and not their characteristic behaviors. The materials that have been tested, which includes: a standard 3D printing polymer polylactide; a commercially available steel feedstock Ultrafuse® 316L; both magnesium and titanium in metal injection molding grade, and in 3D printing grade, show a range of characteristics. The thermal and rheological behaviors of these materials must be understood to optimize the parameters of the process. The most important thermal values are the degradation, melting, and crystalizing temperatures. The critical rheological values are the complex viscosity and dynamic moduli. Printing tests were completed to associate the material properties with the quality of printing. A basic geometry sample print was able to be produced by each material in varying quality. A weak correlation between the material properties, processing parameters, and printing results could be made because of many factors of the combined effects and the strong influence of the 3D printer hardware on the printing quality of the samples. With these new insights into these complex materials, the development of new polymer-metal feedstocks can be studied and developed more scientifically. Eventually, this material will be used on an industrial scale and will widen the possibilities of manufacturing with fused filament fabrication.
