A method for improving corrosion resistance of a high abundance rare earth permanent magnet by high temperature oxidation is provided. By the oxidation at 700 ~ 1000° 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.

A method for improving the corrosion resistance of NdFeB materials is provided. The method includes in-situ growing a layer of oxide, nitride, or oxynitride on the surface of NdFeB magnet correspondingly by performing at least one of an oxidation treatment and a nitridation treatment at low temperature in a range of 200˜400° C., thereby significantly improving the corrosion resistance of the magnet. The method is simple to operate, low-cost, green, safe, and efficient. Depending on the parameters of the low-temperature oxidation and/or nitridation treatment, the thickness of the oxide, nitride, or oxynitride layer is adjustable from 10 nm to 100 μm, which can improve the corrosion resistance of the magnet while maintaining excellent magnetic properties. Moreover, the thin surface layer is in-situ grown on the NdFeB substrate, which is strong and stable over a long service period and can be applied for mass production.

The disclosed technology provides a nanofunctionalized magnetic material feedstock comprising: from 50 wt % to 99.5 wt % of magnetic microparticles having an average microparticle effective diameter from 1 micron to 500 microns; from 0.4 wt % to 40 wt % of one or more rare earth elements; and from 0.1 wt % to 10 wt % of metal-containing inoculant nanoparticles, wherein at least 1 wt % of the inoculant nanoparticles are chemically and/or physically disposed on surfaces of the magnetic microparticles. The nanofunctionalized magnetic material feedstock is processed using high-throughput laser-based additive manufacturing to optimize the architecture of NdFeB or other magnets, generating site-specific, demagnetization-resistant microstructures. This disclosure teaches a rapid, single-step laser-based process to tailor the easy axis alignment, grain size, and microstructure of a permanent magnet at corners and edges to resist demagnetization.

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.

The disclosed technology provides a cladded permanent magnet comprising: a core magnet region containing a core magnetic material; and a magnet cladding containing a shell magnetic material comprising (i) a magnetic compound that is chemically the same as the core magnetic material, (ii) one or more rare earth elements, and (iii) metal-containing inoculant nanoparticles, wherein the magnet cladding is disposed on the core magnet region, wherein the magnet cladding has at least 10% higher ambient-temperature magnetic coercivity compared to the core magnet region. The cladded permanent magnet is made via high-throughput laser-based additive manufacturing to optimize the architecture of NdFeB or other magnets, generating site-specific, demagnetization-resistant microstructures. This disclosure teaches a rapid, single-step laser-based process to tailor the easy axis alignment, grain size, and microstructure of a permanent magnet at corners and edges to resist demagnetization.

A permanent magnet of an embodiment comprises: a base magnet represented by a-b-c (a includes a rare earth-based element, b includes a transition element, and c includes boron (B)); and a coating layer coated on a surface of the base magnet, wherein the coating layer comprises a compound containing a metal having magnetism, the compound including: a phosphor (P); and a metal belonging to the fourth period in the periodic table.

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.

A process is provided for the production of rare earth magnets comprising the steps of exposing a rare earth alloy to hydrogen gas at an elevated temperature so as to effect hydrogenation and disproportionation of the alloy, mechanically processing the disproportionated alloy, and degassing the processed alloy so as to effect hydrogen desorption and recombination of the alloy. The process of the invention finds use in the production and shaping of rare earth magnets, and may be particularly applicable to the production of thin magnetic sheets.

The disclosure relates to a preparation device and method of forming a ceramic coating on a sintered type NdFeB permanent magnet. The preparation device comprises a holding barrel, a pump body, a spraying system, and a fixture mechanism. The pump body is connected with the holding barrel and the spraying system and the spraying system is located above the fixture mechanism and there is a distance between the spraying system and the fixture mechanism. The fixture mechanism is connected with a recovery bucket through a pipeline, and the recovery bucket is connected with the holding barrel through the pipeline. The spraying system comprises a nozzle, wherein the inlet of the nozzle is connected with the pipeline of the pump body. The fixture mechanism comprises a support plate, an upper recovery trough plate and a lower recovery trough plate, wherein the lower recovery trough plate is located above the support plate.

The present disclosure relates to a fabrication process for a current transformer. For example, the process may include wrapping first windings around a first core half of a magnetic core of a current transformer. The process may include wrapping second windings around a second core half of the magnetic core. The magnetic core may be inserted into an overmold tool. The process may include overmolding a first overmold over the first core half of the magnetic core and a second overmold over the second core half of the magnetic core. After overmolding, the magnetic core may be cut in half.