H01F1/083

Extrudable magnetic ink and novel 3D printing method to fabricate bonded magnets of complex shape

A magnetic ink composition for three-dimensional (3D) printing a bonded magnet is provided. The magnetic ink composition includes magnetic particles, a polymer binder and a solvent. A 3D printing method for fabrication of a bonded magnet using the magnetic ink composition is also provided.

IRON NITRIDE POWDER WITH ANISOTROPIC SHAPE
20180001385 · 2018-01-04 ·

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one a″-Fe16N2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one a″-Fe16N2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Method for manufacturing field magnet

A field magnet manufacturing method where a bonded magnet's inner surface press-fitted in a yoke has a certain accuracy irrespective of the accuracy of the yoke's outer circumferential surface. A cylindrical bonded magnet from binding magnet particles with a thermosetting resin is fixed in a tubular yoke of magnetic material. The method includes reheating and softening the bonded magnet after thermal curing; and press-fitting in the bonded magnet after the softening step from a tapered portion on one end side of the yoke to press the bonded magnet's outer circumferential surface against the yoke's inner surface. The press-fitting includes feeding the bonded magnet relatively into the yoke while allowing a relative posture variation between the bonded magnet and the yoke so the bonded magnet's inner surface to be remolded into a shape along the inner surface of the yoke exhibits almost the same accuracy as the yoke's inner surface.

PRODUCTION OF Fe16N2 COMPOUND AS A PERMANENT MAGNET

A production method of a Fe.sub.16N.sub.2 based permanent magnet includes the following steps: 1) obtaining a Fe.sub.16N.sub.2 compound in a form of micro flakes by applying a nitriding process to α′-Fe powders of micro or nano sizes; 2) forming a structure by combining a polymer material with the Fe.sub.16N.sub.2 compound and utilizing a 3D printer; and 3) applying a magnetization process to the structure obtained in step 2 to obtain a magnetized structure and carrying out a heat treatment process to the magnetized structure to obtain the Fe.sub.16N.sub.2 based permanent magnet. The production method is continuous, less difficult, and less costly compared to the production of previous permanent magnets.

Iron nitride powder with anisotropic shape

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one α″-Fe.sub.16N.sub.2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one α″-Fe.sub.16N.sub.2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Magnet structure, rotational angle detector, and electric power steering device
11616421 · 2023-03-28 · ·

A magnet structure is a magnet structure for a TMR element which is an MR element. The magnet structure includes a bonded magnet compact that has a first main surface facing the TMR element, and a second main surface on a side opposite to the first main surface; and a tubular member that supports the bonded magnet compact. The bonded magnet compact has a gate portion which is provided on the second main surface and includes a gate mark formed by performing injection molding. The gate portion is provided at a position overlapping a center on the second main surface when seen from the second main surface side.

METHOD FOR PREPARING HIGH-PERFORMANCE ANISOTROPIC RARE-EARTH-FREE PERMANENT MAGNETS

The present invention discloses a method for preparing high-performance anisotropic rare-earth-free permanent magnets, comprising the steps of: forming alloy ingots by melting according to a nominal composition of Mn.sub.xBi.sub.100-x, (45≤×≤55); then coarsely crushing the alloy ingots and passing the crushed material through a 100-mesh sieve to obtain coarse powder; putting an appropriate amount of Mn.sub.xBi.sub.100-x alloy coarse powder obtained into a ball-milling tank together with non-magnetic steel balls, with a ratio of ball to powder of 10:1; adding an appropriate amount of ethanol as solvent, and then adding a non-ionic surfactant polyvinylpyrrolidone (PVP) accounting for 5-15% of the power mass to assist in low-energy ball milling; washing the slurry obtained in anhydrous ethyl alcohol, and orientating and curing the washed magnetic powder in a magnetic field after adding binder to obtain high-performance anisotropic Mn—Bi alloy magnets finally.

SOFT BISTABLE MAGNETIC ACTUATOR AND FABRICATION METHOD THEREOF, FATIGUE TESTING DEVICE AND AUTO UNDERWATER VEHICLE

Disclosed are a soft bistable magnetic actuator, a fabrication method thereof, a fatigue testing device, and an auto underwater vehicle. The method for fabricating the soft bistable magnetic actuator includes the following operations: casting a soft precursor by injection molding, wherein the soft precursor consists of a soft deformable portion and a soft peripheral portion surrounded, the soft deformable portion is made of magnetic particles and polymer, and the soft peripheral portion is made of a magnetic particle, a mixture of organic liquid, and polymer; and extracting the organic liquid by an organic solvent shrinks the soft peripheral portion, buckles the soft deformable portion towards one side.

Composite component comprising ring-shaped bonded magnet and method of manufacturing the same

The present invention relates to a composite component including a metal component having a substantially cylindrical shape or a substantially annular shape, and a ring-shaped bonded magnet disposed on the outer periphery of the metal component, the ring-shaped bonded magnet containing a thermoplastic resin, magnetic particles, and rubber particles.

Process for producing R-T-B-based rare earth magnet particles, R-T-B-based rare earth magnet particles, and bonded magnet

A process for producing R-T-B-based rare earth magnet powder having excellent coercive force and high remanent flux density. A process for producing R-T-B-based rare earth magnet powder by HDDR treatment, in which a raw material alloy for the R-T-B-based rare earth magnet powder includes R (wherein R represents at least one rare earth element including Y), T (wherein T represents Fe, or Fe and Co) and B (wherein B represents boron), and has a composition including R in an amount of between 12.0 atom % and 17.0 atom %, and B in an amount of between 4.5 atom % and 7.5 atom %; the HDDR treatment includes a DR step including a preliminary evacuation step and a complete evacuation step; and a rate of pressure reduction caused by evacuation in the preliminary evacuation step is not less than 1 kPa/min and not more than 30 kPa/min.