Functionalizing magnet additive manufacturing with in-situ magnetic field source

Abstract

Additive manufacturing via 3-D printing technologies have become a frontier in materials research, including its application in the development and recycling of permanent magnets. This work addresses the opportunity to integrate magnetic field sources into 3-D printing process in order to enable printing, alignment of anisotropic permanent magnets or magnetizing of magnetic filler materials, without requiring further processing. A non-axisymmetric electromagnet-type field source architecture was designed, modelled, constructed, and installed to a fused filament commercial 3-D printer and tested. The testing was performed by applying magnetic field while printing composite anisotropic Nd-Fe-B+Sm-Fe-N powders bonded in Nylon12 (65vol.%) and recycled Sm-Co powder bonded in PLA (15vol.%). Magnetic characterization indicated that the degree-of-alignment of the magnet powders increased both with alignment field strength (controlled by the current applied to the magnetizing system) and the printing temperature. Both coercivity and remanence were found to be strongly dependent on the degree-of-alignment except for printing performed below but near the Curie temperature of Nd-Fe-B (310°C). Under applied field of 0.15 kOe, Sm-Co and hybrid Nd-Fe-B/Sm-Fe-N printed samples showed degrees-of-alignment of 83% and 65%, respectively. The variations in coercivity were consistent with previous observations in bonded magnet materials. This work verifies that integration of magnetic field sources into 3-D printing processes will result in magnetic alignment of particles while ensuring that other advantages of 3-D printing are retained.

Development and Characterization of Field Structured Magnetic Composites

“…The bar graphs indicate the efficacy of field structuring to achieve higher magnetic properties, i.e., saturation, remanence, and coercivity for the in-plane direction are consistently higher for samples S2 and S3 compared to the isotropic sample S4. Present observations are congruent to magnetic composites containing field structured particles in a thermoplastic matrix [ 31 , 32 ]. Overall, the present study validates the effectiveness of field structuring magnetic particles in thermoset polymers using a permanent magnet array, enabling an efficient fabrication of anisotropic magnetic composites for a variety of applications in electrical and electronic devices.…”

“…In-situ magnetic alignment using an electromagnet integrated with fused deposition modelling equipment was tested on anisotropic NdFeB/samarium ferrite nitride powders reinforcing a Nylon 12 matrix. It was found that the degree of alignment was a function of applied magnetic field and printing temperature [ 32 ]. It was additionally noted that alignment studies were primarily conducted in thermoplastic polymer-bonded permanent magnets.…”

Manufacturing Processes for Permanent Magnets: Part II—Bonding and Emerging Methods

“…Big area additive manufacturing (BAAM) is a system developed by Cincinnati Inc. to fabricate large parts via a material extrusion method which has produced bonded Nd-Fe-B magnets with attractive properties. [16][17][18][19][20][21][22] BAAM deposits layers of molten thermoplastics with magnet particles by extruding the material through a nozzle. The thermoplastic solidifies rapidly after deposition, allowing a large magnet to be built quickly.…”

Design and Fabrication of a Magnetic Actuator for Torque and Force Control Estimated by the ANN/SA Algorithm

“…Electromagnetism principles and magnetic actuators have been implemented in various applications such as metal forming, where a solenoid with 15 turns generates a magnetic force to push a light metal in order to form a cellphone case [1], real-time production of magnetic materials with the 3D printer in additive manufacturing is feasible by aligning the particles with the magnetic field [2]. In addition, magnetic levitation can be used to design a stable suspension for metal additive manufacturing, which results in substrate elimination [3].…”