A method for producing a sintered R-iron (Fe)-boron (B) magnet, the method including: (1) producing a sintered magnet R1-FeB-M; (2) washing the sintered magnet using an acid solution and deionized water, successively, and drying the sintered magnet to yield a treated magnet; (3) mixing a heavy rare earth element powder RX, an organic solid powder EP and an organic solvent ET to yield a slurry RXE, coating the slurry RXE on the surface of the treated magnet, and drying the treated magnet to yield a treatment unit; and (4) heating, quenching, and then aging the treatment unit.

A rare-earth element including a magnet body containing a rare-earth element, and a protective layer formed on a surface of the magnet body. The protective layer may include a first layer covering the magnet body and containing a rare-earth element, and a second layer covering the first layer and containing substantially no rare-earth element. Another protective layer in accordance may include an inner protective layer and an outer protective layer successively from the magnet body side. The outer protective layer is any of an oxide layer, a resin layer, a metal salt layer, and a layer containing an organic-inorganic hybrid compound.

Coatings for magnetic materials, such as rare earth magnets, are described. The coatings are designed to reduce or prevent the release of one or both of nickel and cobalt from the coatings or from the underlying magnetic material. The coatings are designed to resist corrosion and release of nickel and cobalt when exposed to moist conditions. The coatings are also designed to be robust enough to withstand damage due to scratch forces. In some embodiments, the coatings include multiple layers of one or of metal and non-metal materials. The coated magnets are well suited for use in the manufacture of wearable consumer products.

A method for improving corrosion resistance of a high abundance rare earth permanent magnet by high temperature oxidation is provided. By the oxidation at 7001000 C., a rare earth oxide film grows in-situ on the surface, which can greatly improve the corrosion resistance of the high abundance rare earth permanent magnet. The method makes full use of phase formation rule and diffusion kinetic behavior of high abundance rare earth elements La/Ce/Y, which is different from other rare earth elements Nd/Pr/Dy/Tb. The method grows the rare earth oxide film in situ with strong adhesion to the matrix, which can not only greatly improve the corrosion resistance of the magnet, but also improve the magnetic and mechanical properties. The method has advantages of green environmental protection, long service life and simple process, and can be popularized and applied in large quantities.

There is provided a compression-bonded magnet with a case, which can realize high magnetic properties, high corrosion resistance and high durability strength even at low cost. The compression-bonded magnet with a case is a compression-bonded magnet with a case 1, comprising: a compression-bonded magnet 2 comprising a rare earth magnet powder such as an isotropic NdFeB magnet powder and a resin binder of a thermosetting resin; a case 3 for inserting the compression-bonded magnet 2; and a sealing member 4, wherein the compression-bonded magnet 2 is formed by compression-molding a mixture comprising the rare earth magnet powder and the resin binder into a green compact and curing the resin binder contained in the green compact, the rare earth magnet powder is contained in a large amount with respect to the entire compression-bonded magnet (for example, in a volume ratio of 85% to 90%), the sealing member 4 is fixed at an insertion opening part 3a of the case 3, and the compression-bonded magnet 2 is hermetically sealed by the sealing member 4 and the case 3.

The present invention provides a NdFeB magnet including a first film of aluminum having a first predetermined hardness and an anti-corrosive coating of oxidized aluminum having a second predetermined hardness on the first film. The second predetermined hardness is at least eight times the first predetermined hardness. The present invention also provides a method for preparing a hard aluminum film on the NdFeB magnet. The method includes depositing the first film on the NdFeB magnet under vacuum, disposing the NdFeB magnet having the first film on the anode, and subjecting the NdFeB magnet having the first film to the anodic oxidation process under a solution containing an electrolyte present between 15 wt. % to 20 wt. % to form the anti-corrosive coating on the first film to prevent the NdFeB magnet from corroding. The electrolyte is selected from at least one of sulfuric acid, chromic acid, boric acid, and oxalic acid.

Coatings for magnetic materials, such as rare earth magnets, are described. The coatings are designed to reduce or prevent the release of one or both of nickel and cobalt from the coatings or from the underlying magnetic material. The coatings are designed to resist corrosion and release of nickel and cobalt when exposed to moist conditions. The coatings are also designed to be robust enough to withstand damage due to scratch forces. In some embodiments, the coatings include multiple layers of one or of metal and non-metal materials. The coated magnets are well suited for use in the manufacture of wearable consumer products.

This disclosure provides methods and apparatus for adjusting magnetic orientations of different sets of magnets in an array. In one aspect, a first set of magnets in the array can be heated. A magnetic field with a first orientation can be applied to the array of the magnets, and adjusting the magnetic orientations of the first set of magnets to the first orientation of the magnetic field. A second set of magnets in the array can be heated and the magnetic field can have a second orientation. The magnetic orientations of the second set of magnets can be adjusted to the second orientation.

A magnetic article with a corrosion resistant barrier formed from a poly (tetrafluoro-p-xylene) conformal coating or from a parylene conformal coating having a melting point of at least about 430 C. and a moisture vapor transmission less than about 0.5 g-mm/m.sup.2/day at 90% RH and 37 C., the conformal coating being covered with a polysulfone thermoplastic overlayer.

Magnets including a coating and related methods are described herein. The coating may include an aluminum manganese alloy layer. The aluminum manganese alloy layer may be formed in an electroplating process.