Exploring the Relationship Between Dual Material Filament Annealing Temperature and Material Properties

Abstract

The use of additive manufacturing (e.g., AM) in research, industrial, and hobbyist environments has expanded rapidly in recent years. This has resulted in a massive increase in filament types and their potential combinations available for AM. For many of these new materials, the best processing and post-processing conditions are not fully understood. Annealing at high temperatures has been proposed as a method to modify the mechanical properties of dual-material filaments, like tensile strength, but early results suggest that changes may be minor. This research sought to evaluate annealing temperatures' relationship to tensile strength. For high annealing temperatures, we hypothesized that annealing is negatively correlated with tensile strength. To test this theory, dogbones were printed using a filament with a polycarbonate core and acrylonitrile butadiene styrene shell and annealed at different temperatures. The annealed dogbones were tested in a tensile test machine to evaluate the annealed materials’ tensile strength. This study found that annealing at 95°C did not significantly increase the tensile strength, while annealing at 135°C decreased tensile strength. However, annealing at 95°C significantly reduced the overall variation in tensile strength (n=10). Further research is needed to determine the precise relationship between annealing temperature and tensile strength of dual material filaments, as well as to evaluate other potential relationships to material properties such as bending strength.