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Bonded magnetic composites combine the cost-effectiveness, low density, and manufacturing flexibility of conventional polymer binders with the unique magnetic characteristics of magnetic powders/fillers to form multifunctional magneto polymeric composites that offer superior properties to conventional sintered magnets. In this study, a co-rotating twin screw extruder was used to fabricate 20 and 40 wt.% strontium ferrite/polyamide 4.6 bonded magnetic composites viable for fused filament fabrication 3D printing. The characterization conducted on the bonded magnetic composites was scanning electron microscopy, simultaneous differential thermogravimetry, and vibrating sample magnetometry. The microstructure of the bonded composite exhibited a uniform platelet morphology of the strontium ferrite magnetic particles. There was no observable depreciation in the melting transitions, which suggests a thermally resistant magnetic composite. An appreciable increment in % crystallinity of 13 and 20% for 20wt. % and 40wt. % strontium ferrites bonded magnets were observed. This is attributable to the heterogeneous nucleation phenomenon, where the metal powders act as nucleation sites for increased crystalline domains. The bonded composite exhibited significant magnetic anisotropy, with the remanence (Mr), which is the most important property for magnetic application significantly increasing to 49.8% along the easy direction in comparison to the hard axis. This suggests the viability of the fabricated bonded composites in viable in producing anisotropic bonded magnetic devices, which are considered to exhibit stronger magnetic properties.
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This content will become publicly available on May 26, 2026
Development of strontium ferrite/polyamide 12 and neodymium iron boron/polyamide 12 composites using additive manufacturing
Polymer matrix composite materials with magnetic properties obtained by the addition of micron-size particles of neodymium iron boron (NdFeB) and strontium ferrite for fused filament fabrication (FFF) are becoming attractive because of their potential applications in the health and automotive industries. Additionally, the design flexibility and low cost of additive manufacturing processes encourage the scientific community to create the materials and understand the properties of the parts obtained with such methods. For example, the micron-size particles of NdFeB and two different types of strontium ferrites, OP-56 and OP-71, were dispersed in the Polyamide 12 matrix using twin screw extrusion. The monofilaments produced on twin screw extrusion were used to print test samples using an open-source FFF 3D printer. Thermal analysis shows a heat flow improvement in the composites compared to neat polyamide 12. Flexural and tensile strengths of the NdFeB/PA12 and OP-71/PA12 composites were reduced, whereas OP-56/PA12 composites showed an improvement of 6% compared to neat PA12. On the other hand, the tensile moduli of OP-71/PA12, OP-56/PA12, and NdFeB/PA12 composites increased by 5.5%, 48.9%, and 25.13%, respectively.
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- PAR ID:
- 10651421
- Publisher / Repository:
- STM Journals
- Date Published:
- Journal Name:
- Journal of nanoscience nanoengineering and applications
- ISSN:
- 2231-1777
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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