An anisotropic bonded magnet and a preparation method thereof are provided. By stacking magnets having different magnetic properties and/or densities, the magnets in the middle have high properties and the magnets at two ends and/or the periphery have low properties, thereby compensating for a property deviation caused by a difference in pressing densities during a pressing process, and improving the property uniformity of the magnets in an axial direction. The method solves the problem of “low in the middle and high at two ends” caused by the phenomenon of non-uniform magnetic field orientation and density along a height direction during orientation and densification.

An anisotropic bonded magnet and a preparation method thereof are provided. Through a method of stacking magnets which are different in content of SmFeN and/or have different densities, the magnets in the middle have high properties and the magnets at two ends and/or the periphery have low properties, thereby compensating for a property deviation caused by a difference in densities during a pressing process, and improving the property uniformity of the magnets in an axial direction. The method avoids the phenomenon of non-uniform magnetic field orientation and density in a height direction during orientation and densification as well as the phenomenon of low in the middle and high at two ends.

A responsive material having an elastomeric matrix in which ferromagnetic particles are dispersed so as to have a predetermined magnetization pattern which, when exposed to an external magnetic field, changes the shape of the responsive material from an initial shape to a predetermined transformed shape dictated by the magnetization pattern. An initial shape of the responsive material is formed by direct ink printing while applying magnetic fields to a dispensing nozzle to align the particles and gives rise to the desired magnetization pattern.

An electric machine that is configured to propel a vehicle includes a stator and a rotor. The stator has windings that are configured to generate magnetic fields. The rotor has a plurality of magnetic blocks that interacts with the magnetic fields to produce rotational motion. Each of the plurality of magnetic blocks is segmented into a plurality of permanent magnets. Adjacent permanent magnets within each magnetic block are separated from and secured to each other via an intermediate electrically insulating material. The intermediate electrically insulating material is comprised of magnetic particles that are suspended in an adhesive matrix.

A method of producing a compound for bonded magnets, the method including: heat-curing a thermosetting resin and a curing agent having a ratio of the number of reactive groups of the curing agent to the number of reactive groups of the thermosetting resin of at least 2 but not higher than 11 to obtain an additive for bonded magnets; and kneading the additive for bonded magnets, magnetic powder, and a thermoplastic resin to obtain a compound for bonded magnets in which a filling ratio of the magnetic powder is at least 91.5% by mass.

A method for producing a bonded magnet, comprising: (i) low-shear compounding of a thermoplastic polymer and magnetic particles to form an initial homogeneous mixture thereof; (ii) feeding the initial homogeneous mixture into a plasticator comprising a low-shear single screw rotating unidirectionally toward a die orifice and housed within a heated barrel to result in heating of the initial homogeneous mixture until the thermoplastic polymer melts and forms a further homogeneous mixture, wherein said further homogeneous mixture is transported within threads of the single screw towards the die orifice and exits the die orifice as a solid pellet; (iii) conveying the solid pellet into a mold and compression molding the pellet in the mold, to form the bonded magnet, wherein the bonded magnet possesses a magnetic particle loading of at least 80 vol % and exhibits one or more magnetic properties varying by less than 5% throughout the bonded magnet.

Disclosed is a method of magnetising a substrate comprising the steps of: preparing a magnetising coat by dispersing a plurality of particles of at least one magnetisable material in a binder; applying the magnetising coat on a surface of the substrate; setting the magnetising coat; and magnetising the magnetisable material in the magnetising coat by exposing the magnetising coat to a magnetic field.

The disclosure provides a preparation method, which comprises: providing a moulding die for a ring-shaped sintered Nd—Fe—B magnet; placing a Nd—Fe—B magnetic powder into the mould cavity of the moulding die in a loosely packed state, the loosely packed height of the Nd—Fe—B magnetic powder is L;

placing a flexible cylindrical core into the loosely packed Nd—Fe—B magnetic powder at a L/2 position, wherein an axial direction of the flexible cylindrical core is horizontal and parallel to the direction of a magnetic field in the mould cavity;

applying a vertical pressure to the Nd—Fe—B magnetic powder to obtain a ring-shaped green block assembly with the flexible cylindrical core embedded;

after encapsulating and isolating the ring-shaped green block assembly, applying an isostatic pressure to the ring-shaped green block assembly;

sintering the ring-shaped green block assembly to obtain a ring-shaped sintered blank;

thermally aging, grinding and slicing the ring-shaped sintered blank.

The present invention provides R-T-B-based rare earth magnet particles comprising no expensive rare resources such as Dy and having an excellent coercive force which can be produced by HDDR treatment without any additional steps. The present invention relates to R-T-B-based rare earth magnet particles comprising crystal grains comprising a magnetic phase of R.sub.2T.sub.14B, and a grain boundary phase, in which the grain boundary phase has a composition comprising R in an amount of not less than 13.5 atom % and not more than 35.0 atom % and Al in an amount of not less than 1.0 atom % and not more than 7.0 atom %. The R-T-B-based rare earth magnet particles can be obtained by controlling heat treatment conditions in the DR step of the HDDR treatment in the course of subjecting a raw material alloy to the HDDR treatment.

Provided are a rare earth magnet precursor having a roughened structure on a surface or a rare earth magnet molded body having a roughened structure on a surface, and a method for manufacturing the same. In the rare earth magnet precursor or the rare earth magnet molded body, recesses and protrusions are formed on the surface having the roughened structure, and the recesses and protrusions satisfy at least one of the following (a) to (c): (a) an arithmetic mean height (Sa) (ISO 25178) from 5 to 300 μm, (b) a maximum height (Sz) (ISO 25178) from 50 to 1500 μm, and (c) a developed interfacial area ratio (Sdr) (ISO 25178) from 0.3 to 12.