O.K. Arigbabowo, P.U. Karkhanis, W.J. Geerts, J.S. Tate
Texas State University,
United States
Keywords: bonded magnetic composites (BMCs), 3D printing strontium ferrite powder polyamide 4.6, twin-screw extrusion, high-temperature fused filament fabrication (FFF), mechanical properties
Summary:
Bonded magnetic composites (BMCs) are emerging as next-generation materials, offering a feasible alternative to traditional sintered magnets. These applications are electric motors, sensors, magnetic storage devices, and other magnetic systems. Bonded magnets have enhanced the structural integrity of the fabricated magnetic material by using a polymer binder to induce more flexibility. One significant advantage of bonded magnetic composites (BMCs) is their suitability for manufacturing "near net shaped" parts in 3D printing. This approach opens new possibilities for advanced manufacturing. Using additive manufacturing techniques, complex and optimized designs can be created that would be difficult or impossible to achieve with traditional methods like sintering. The layer-by-layer process allows for precise control over material placement on the print bed, enabling the integration of features such as internal structures, custom geometries, and gradient material properties. Additionally, this method promotes the efficient use of raw materials, minimizing wastage and lowering production costs. It also facilitates rapid prototyping, allowing for quick testing and iteration of designs. Therefore, this study investigates the mechanical performance of BMCs, specifically using polyamide 4.6 as the matrix, which is a high-performance polymer known for its strength, heat resistance, and dimensional stability and strontium ferrite powder anisotropic ceramic ferrite powder as the magnetic reinforcement for the bonded magnetic composites. This composite filament was fabricated via a twin-screw extrusion process which compounds filler and matrix together to form a composite utilizing shear force from twin screws to intermix and form a uniform composite with well-dispersed strontium ferrite and subsequently 3D-printed using a high-temperature fused filament fabrication (FFF) process with optimized 3D printing parameters. Mechanical properties of composites, such as tensile and flexural strength, were assessed according to ASTM standards. Factors like packing fraction and the size of the strontium ferrite reinforcement appear to influence the mechanical performance of the composites. These findings offer valuable insights into the structural integrity of bonded magnetic composites. Part of this work was supported by an MRI Grant under award 2216440