Hybrid metal/thermoplastic composites for FDM-type additive manufacturing

Hybrid material systems, where two materials with similar melting temperatures are combined to form a new compound, represent a possible avenue to expand the materials palette available for 3-D printing platforms such as fused deposition modeling (FDM™). In general, the morphology of filler materials in thermoplastic composites is unchanged before and after combining with a polymer matrix. However, the processing of hybrid material systems in FDM™-type processing allows for the possibility of manipulating the morphology of the filler material. The work presented here demonstrates the development of three different hybrid (polymer–metal) blends for 3-D printing platforms based on FDM™ technology. Tin-bismuth (SnBi) alloy powder was combined with three thermoplastic materials: (1) acrylonitrile butadiene styrene (ABS), (2) polylactic acid, and (3) a polymer blend composed of ABS and styrene ethylene butylene styrene containing a maleic anhydride graft (SEBS-g-MA). A notable feature observed through the use of scanning electron microscopy (SEM) was the drawing of the spherical SnBi particles into wires, leading to an in situ reinforcement. The efficacy of a silane functionalization process was also noted, though the material processing temperatures were well above the melting temperature of the SnBi particles.