Development of Binding System for Metal Fused Filament Fabrication of AlSi10Mg Alloy

Additive manufacturing technology through 3D printing can efficiently produce parts with complex geometries using smaller, portable equipment. 3D printing plays a significant role in manufacturing polymer prototypes and products in various areas. One promising area of research involves incorporating metal powder into polymer filaments for 3D printing, aiming to expand the versatility of the technique and provide an alternative to conventional approaches such as Fused Filament Manufacturing (FFF). The binder polymer formulation plays a crucial role in the success of the manufacturing process. This study presents the development of a specific binding system for the 3D printing of AlSi10Mg filaments. The binder includes low-density polyethylene (LDPE) and thermoplastic starch (TPS). LDPE contributes to structural integrity during binder dissolution, reduces viscosity, and increases strength and stiffness. Meanwhile, TPS, besides being biodegradable, provides flexibility to the filaments. The study included an analysis of the shape and size distribution of metallic powder particles before their incorporation into the polymeric matrix. The composite filaments were produced using reactive extrusion (REX), being mechanically characterized and evaluated for their homogeneity. The reactive extrusion method demonstrated effectiveness in the production of homogeneous composite filaments in relation to the metallic filler incorporated into the thermoplastic polymer blend. Although extruded filaments exhibit inferior mechanical properties compared to thermoplastics generally used in FFF additive manufacturing, the method has potential for application in the manufacture of new composite filament compositions using LDPE and TPS blend matrix as a binding for application in 3D printing.