3D printing of polymer-bonded anisotropic magnets in an external magnetic field and by a modified production process

Abstract

The possibility of producing polymer-bonded magnets with the aid of additive processes, such as 3D printing, opens up a multitude of new areas of application. Almost any structures and prototypes can be produced costeffectively in small quantities. Extending the 3D printing process allows the manufacturing of anisotropic magnetic structures by aligning the magnetic easy axis of ferromagnetic particles inside a paste-like compound material along an external magnetic field. This is achieved by two different approaches: First, the magnetic field for aligning the particles is provided by a permanent magnet. Secondly, the 3D printing process itselfs generates an anisotropic behavior of the structures. An inexpensive and customizable end-user fused filament fabrication 3D printer is used to print the magnetic samples. The magnetical properties of different magnetic anisotropic Sr ferrite and SmFeN materials are investigated and discussed.

Fabrication and Characterization of Polymer-Bonded Flexible Anisotropic Micro-Magnet Arrays

“…1) indicated that a shorter soft-curing of 30 minutes is better suited to structures of width < 100 µm, meaning the powder appears homogeneously distributed in the binder, while the longer time of 60 minutes is better suited to larger structures. The results presented hereafter concern arrays of micro-pillars made using a Si mould prepared with a mask of square features with in-plane dimensions 300x300 μm 2 . The Si was etched 300 μm in depth, and the width of the etched holes tapered down from 300 µm at the surface of the mould to roughly 200 µm at the base of the etch.…”

“…Nevertheless, bonded magnets are widely used for the following reasons: firstly, they are cheaper than sintered versions in both material and fabrication cost, secondly, they can be easily manufactured in complex geometries, and finally, the mechanical properties can be tuned according to the choice of matrix. Traditional fabrication routes for polymer bonded magnets include calendering, injection moulding, extrusion, and compression bonding [1] while more recently 3D printing of polymer bonded magnets has been explored, in some cases down to the mm size range [2]- [7]. Down-scaling the size of magnets opens new opportunities for their use in micro-devices with applications in fields as diverse as telecommunications, energy management and bio-medicine.…”

3D Printing of Flexible Composites via Magnetophoresis: Toward Medical Application Based on Low‐Frequency Induction Heating Effect

“…At that position, an undesired force acting on the magnetic particle could lead to the unfavorable magnetization of the sample. [ 29 ]…”

Effects of Carbon Doping and Annealing Temperature on Magnetic MnAl Powders and MnAl Polymeric Composites

“…The dimensions of magnets are therefore limited by the compaction mold. Additive manufacturing currently opens up opportunities for unconventional designs of rare-earth magnets [1][2][3][4][5], hard ferrites [5,6], and iron oxides [7,8], as well as recycled magnets [9]. Novel magnets of varying shapes and sizes can be printed out.…”