Patent classifications
H01F41/0273
CE-CONTAINING SINTERED RARE-EARTH PERMANENT MAGNET WITH HAVING HIGH TOUGHNESS AND HIGH COERCIVITY, AND PREPARATION METHOD THEREFOR
The present invention relates to a Ce-containing sintered rare earth permanent magnet with high toughness and high coercivity and a method of preparing the magnet, belonging to the technical field of rare earth permanent magnetic materials. The magnet is prepared by steps of raw material batching, strip casting, hydrogen decrepitation and jet milling, powder orientating and forming, sintering and heat treatment. The materials of the permanent magnet comprise the main phase alloy powders and the Ce added phase alloy powders, wherein the Ce added phase alloy is a magnetic phase or a non-magnetic liquid-phase alloy; and the Ce added phase alloy accounts for 5% to 30% of the total weight of the permanent magnet, and the remainder is the main phase alloy. During the jet milling stage, a certain concentration of oxygen is added into the inert gas, so that the final magnet has an oxygen content of 1500 to 2500 ppm. The Ce-containing dual-alloy magnet prepared in accordance with the present invention has high coercivity, and the intrinsic coercivity (H.sub.cj) is up to 17 to 28.73 kOe. The magnet of the present invention has good fracture toughness which is increased by 10% to 30% as compared with the conventional Nd—Fe—B sintered magnet. The magnet of the present invention can meet needs of high-end applications such as wind power generation, new energy vehicles, and the like, and greatly expands the application fields of Ce-containing magnets.
Method and assembly for producing a magnet
Method and assembly for producing a magnet. A method of manufacturing a magnet includes transferring magnetic powder into a die cavity. The die cavity has a first side and a second side opposite to the first side. First magnetic flux lines are induced to extend into the magnetic powder through the first side and orthogonal to the first side. The first magnetic flux lines extend out of the magnetic powder through a top surface of the magnetic powder. Second magnetic flux lines are induced to extend into the magnetic powder through the second side and orthogonal to the second side. The second magnetic flux lines extend out of the magnetic powder through the top surface of the magnetic powder. Pressure is applied to the magnetic powder disposed within the die cavity.
PROCESSING OF ANISOTROPIC PERMANENT MAGNET WITHOUT MAGNETIC FIELD
A method of processing an anisotropic permanent magnet includes forming anisotropic flakes from a hulk magnet alloy, each of the anisotropic flakes having an easy magnetization direction with respect to a surface of the flake and combining the anisotropic flakes with a binder to form a mixture. The method further includes extruding or rolling the mixture without applying a magnetic field such that the easy magnetization directions of the anisotropic flakes align to form one or more layers having a magnetization direction aligned with the easy magnetization directions of the anisotropic flakes, and producing the anisotropic permanent magnet from the layers having the magnetization direction such that the anisotropic permanent magnet has a magnetization with. a specific orientation.
Method of manufacturing permanent magnets
A continuous method of manufacturing permanent magnets and the permanent magnets created thereby. A fine powder is created from a combination of magnetic metals. The powder (a metal alloy) is placed in a non-magnetic container of any desired shape which could be, for example, a tube. The metal alloy and tube are swaged while a magnetic field is applied. Once swaging is complete, the metal alloy and tube are sintered and then cooled. Instead of sintering, a bonding agent can mixed into the powder. Following cooling, the metal alloy is magnetized by placing it between poles of powerful electromagnets with the desired field direction. The process of the invention enables mass-produced, cost-effective PM products, which are more robust, easily assembled into products, enables new “wire like” shapes with arbitrary magnetization direction. The process enables mass production of permanent magnets of any desired cross section, produces permanent magnets continuously that may be cut to any length, and may, in an embodiment, result in directional magnets.
SYNTHESIS OF HIGH PURITY MANGANESE BISMUTH POWDER AND FABRICATION OF BULK PERMANENT MAGNET
A synthesis process is disclosed for fabrication of mass quantities of high-purity α-MnBi magnetic powder and subsequent bulk permanent magnet. An illustrative process includes certain steps that include: multiple annealing, multiple comminuting such as multiple ball milling, forming a non-magnetic phase on and/or in the powder particles at particle grain boundaries before particle consolidation such as pressing, and magnetic annealing of a pressed compact. A reproducible and high productive synthesis process is created by combining these steps with other steps, which makes possible production of mass quantities of MnBi powder and bulk magnets with high performance.
RADIATION-ORIENTED SINTERED ARC-SHAPED ND-FE-B MAGNET, A MANUFACTURING METHOD THEREOF, AND A CORRESPONDING MANUFACTURING DEVICE
The disclosure provides a method for preparing a radiation-oriented sintered arc-shaped Nd—Fe—B magnet. The method comprises: providing a Nd—Fe—B powder and a molding device; performing a first sub-step of align pressing including filling the arc-shaped cavity of the molding device with a first powder loading of the Nd—Fe—B powder, performing a first magnetization of the Nd—Fe—B powder, and mold pressing the Nd—Fe—B powder to form a first green body; performing a second sub-step of align pressing including filling the arc-shaped cavity of the molding device with a second powder loading of the Nd—Fe—B powder, performing a second magnetization of the Nd—Fe—B powder, and mold pressing the Nd—Fe—B powder to form a second green body; and sintering and annealing the second green body to obtain an arc-shaped Nd—Fe—B magnet. Further aspects of the disclosure are a molding device useful for the preparation method and a radiation-oriented sintered arc-shaped Nd—Fe—B magnet obtained by the method.
ANISOTROPIC IRON NITRIDE PERMANENT MAGNETS
Disclosed herein is a permanent magnet comprising: a plurality of aligned iron nitride nanoparticles wherein the iron nitride nanoparticles include α″-Fe.sub.16N.sub.2 phase domains; wherein a ratio of integrated intensities of an α″-Fe.sub.16N.sub.2 (004) x-ray diffraction peak to an α″-α″-Fe.sub.16N.sub.2 (202) x-ray diffraction peak for the aligned iron nitride nanoparticles is greater than at least 7%, wherein the diffraction vector is parallel to alignment direction, and wherein the iron nitride nanoparticles exhibit a squareness measured parallel to the alignment direction that is greater than a squareness measured perpendicular to the alignment direction.
MANUFACTURING METHOD OF SINTERED ND-FE-B PERMANENT MAGNET
The present disclosure refers to a preparation method for improving the coercive force of a sintered Nd—Fe—B magnet and comprises: preparing Nd—Fe—B alloy flakes by a strip casting process, followed by hydrogen decrepitation of the Nd—Fe—B alloy flakes and jet milling to obtain an Nd—Fe—B powder; mixing Nd—Fe—B powder and an amount of 0.1 to 5 wt. % of a nanoparticulate powder in a powder mixing machine to obtain a powder mixture; modification of the powder mixture obtained in step B) under inert conditions in a mechanical mixing equipment such that the particles of the Nd—Fe—B powder are rounded and the nanoparticulate powder adheres to the particle surface of the Nd—Fe—B powder; mixing in a lubricant to the modified Nd—Fe—B powder in a powder mixing machine; and align pressing the modified Nd—Fe—B powder into a green body, sintering the green body, and aging of the obtained sintered Nd—Fe—B magnet.
BONDED MAGNET, BONDED MAGNET COMPONENT, AND BONDED MAGNET PRODUCTION METHOD
A bonded magnet is provided which includes first and second components. The first and second components have first and second non-action surfaces, and first and second action surfaces that intersect the first and second non-action surfaces, respectively. First and second flux groups curve inside the first and second components from the first and second non-action surfaces to the first and second action surfaces, respectively. The areas of the first and second non-action surfaces are greater than the first and second action surfaces, respectively. The flux densities on the first and second action surfaces are higher than the first and second non-action surfaces, respectively. The pole on the first non-action surface is opposite to the second non-action surface. The first and second non-action surfaces are coupled to each other. The first flux groups continuously extend from one to another.
Permanent magnet and method of making permanent magnet
A method includes mixing first and second alloys to form a mixture, pressing the mixture within a first magnetic field to form a magnet having anisotropic particles of the first alloy aligned with a magnetic moment of the magnet, and heat treating the magnet within a second magnetic field to form elongated grains from the second alloy and align the elongated grains with the moment.