# US 10,312,019 B2 · Method for producing a permanent magnet and permanent magnet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,019 B2 - Document ID: US10312019B2 - Status: Granted - Kind: B2 - Application number: 14/442,935 - Filed: 2013-10-24 - Published: 2015-10-15 - Granted: 2019-06-04 - Earliest claimed: 2012-11-14 - Assignees: Volkswagen Aktiengesellschaft - Applicants: Volkswagen Aktiengesellschaft - Inventors: Branislav Zlatkov - Web page: https://patentgrep.com/patent/US10312019B2 ## CPC - H01F 1/0552: {with a protective layer} - B22F 1/054: Nanosized particles - B22F 1/056: {Submicron particles having a size above 100 nm up to 300 nm} - B22F 1/16: Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) - B22F 1/17: Metallic particles coated with metal - B32B 15/012: {one layer being formed of an iron alloy or steel, another layer being formed of aluminium or an aluminium alloy} - B32B 15/013: {one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium} - B32B 15/015: {the said other metal being copper or nickel or an alloy thereof} - C22C 38/002: {containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60} - C22C 38/005: {containing rare earths, i.e. Sc, Y, Lanthanides} - H01F 1/0572: {with a protective layer} - H01F 7/021: {Construction of PM (H01F7/0278 takes precedence; PM compositions H01F1/032)} - H01F 41/0266: {Moulding; Pressing (H01F41/0273 takes precedence; hard magnetic particles H01F1/06, H01F1/11)} - H01F 41/0273: {Imparting anisotropy (methods and devices for magnetising permanent magnets H01F13/003)} - H02K 1/27: Rotor cores with permanent magnets - B22F 1/08: Metallic powder characterised by particles having an amorphous microstructure - B22F 2998/10: Processes characterised by the sequence of their steps - C22C 2200/02: Amorphous - C22C 2202/02: Magnetic - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C22C: ALLOYS (treatment of alloys C21D, C22F) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A method for producing a permanent magnet, comprising the step: (a) providing a powder of a magnetic material, (b) coating the powder particles with a coating of a diamagnetic or paramagnetic coating material, (c) compressing the coated particles to form a pressed part, (d) heat treatment to sinter the coating material at a temperature less than a temperature suitable for sintering the magnetic material, while the coating material transfers to a matrix of a diamagnetic or paramagnetic material, which embeds the particles of the magnetic material, and (e) magnetizing the magnetizable material in an external magnetic field, wherein the steps (c), (d) and (e) are carried out in any order successively or at the same time in any desired combination. The nanostructured permanent magnet that can be produced by mean of said method comprises cores of a permanently magnetic material having a mean particle diameter of no more than 1 μm and a matrix of a diamagnetic or paramagnetic material in which the cores are embedded. ## Claims ### Claim 1 A process for manufacturing a nanostructured permanent magnet, comprising the following steps: (a) providing a powder comprising particles of a magnetic material, (b) coating the powder particles with a diamagnetic or paramagnetic coating material, wherein the step of coating the powder particles comprises a dry deposition process, (c) pressing the coated particles into a compact, (d) sintering the diamagnetic or paramagnetic coating material at conditions where no sintering of the magnetic material occurs, while transferring the diamagnetic or paramagnetic coating material into a continuous matrix of a diamagnetic or paramagnetic material embedding the particles of the magnetic material, wherein the diamagnetic or paramagnetic matrix material is selected from the group consisting of a glass, a glass ceramic, and a ceramic, wherein the glass and the glass ceramic are based on at least one of SiO2, Al2O3, Na2O, K2O, MgO, CaO, B2O3, TiO2, PbO, and P2O5, and the ceramic comprises at least one of mineral silicate ceramics, non-oxide ceramics, and oxide ceramics based on aluminum oxide or beryllium oxide, and (e) magnetizing the magnetic material in an external magnetic field, wherein steps (c), (d) and (e) may be carried out in any desired sequential order or simultaneously in any desired combinations. ### Claim 2 (depends on 1) The process as claimed in claim 1, wherein the step of sintering the diamagnetic or paramagnetic coating material is conducted at a temperature that is less than or equal to a transition temperature or a melting temperature of the coating material. ### Claim 3 (depends on 2) The process as claimed in claim 2, wherein the step of sintering the diamagnetic or paramagnetic coating material is conducted at a temperature that is at least 50 K lower than the transition or melting temperature of the coating material. ### Claim 4 (depends on 1) The process as claimed in claim 1, wherein the step of coating the powder particles comprises using a chemical precursor material of the coating material as a starting material, which, during or after the coating, undergoes a chemical reaction to form the coating material. ### Claim 5 (depends on 1) The process as claimed in claim 1, wherein the powder has a mean particle diameter of 3 μm or less. ### Claim 6 (depends on 5) The process as claimed in claim 5, wherein the powder has a mean particle diameter of 1 μm or less. ### Claim 7 (depends on 6) The process as claimed in claim 6, wherein the powder has a mean particle diameter in the range of 0.1 to 0.6 μm. ### Claim 8 (depends on 7) The process as claimed in claim 7, wherein the powder has a mean particle diameter in the range of 0.2 to 0.4 μm. ### Claim 9 (depends on 1) The process as claimed in claim 1, wherein the mean coating thickness of the coating produced in step of coating the powder particles is 100 nm or less. ### Claim 10 (depends on 9) The process as claimed in claim 9, wherein the mean coating thickness is in the range of 1 to 10 nm. ### Claim 11 (depends on 10) The process as claimed in claim 10, wherein the mean coating thickness is in the range of 2 to 5 nm. ### Claim 12 (depends on 1) The process as claimed in claim 1, wherein the magnetic material is a ferromagnetic metal, or a ferromagnetic metal alloy, selected from RE-TM-B alloys or RE-TM alloys, wherein RE is a rare earth element, TM is a transition metal of the iron group, and B is boron. ### Claim 13 (depends on 1) The process as claimed in claim 1, wherein the dry deposition process is a chemical or physical vapor phase deposition process. ### Claim 14 A process for manufacturing a nanostructured permanent magnet, comprising the following steps: (a) providing a powder comprising particles of a magnetic material, (b) coating the powder particles with a diamagnetic or paramagnetic coating material, wherein the mean coating thickness of the coating produced in step of coating the powder particles is 100 nm or less, (c) pressing the coated particles into a compact, (d) sintering the diamagnetic or paramagnetic coating material at conditions where no sintering of the magnetic material occurs, while transferring the diamagnetic or paramagnetic coating material into a continuous matrix of a diamagnetic or paramagnetic material embedding the particles of the magnetic material, wherein the diamagnetic or paramagnetic matrix material is selected from the group consisting of a glass, a glass ceramic, and a ceramic, wherein the glass and the glass ceramic are based on at least one of SiO2, A12O3 , Na2O, K2O, MgO, CaO, B2O3, TiO2, PbO, and P2O5, and the ceramic comprises at least one of mineral silicate ceramics, non-oxide ceramics, and oxide ceramics based on aluminum oxide or beryllium oxide, and (e) magnetizing the magnetic material in an external magnetic field, wherein steps (c), (d) and (e) may be carried out in any desired sequential order or simultaneously in any desired combinations. ### Claim 15 A process for manufacturing a nanostructured permanent magnet, comprising the following steps: (a) providing a powder comprising particles of a magnetic material, wherein the powder has a mean particle diameter in the range of 0.1 to 0.6 μm, (b) coating the powder particles with a diamagnetic or paramagnetic coating material, (c) pressing the coated particles into a compact, (d) sintering the diamagnetic or paramagnetic coating material at conditions where no sintering of the magnetic material occurs, while transferring the diamagnetic or paramagnetic coating material into a continuous matrix of a diamagnetic or paramagnetic material embedding the particles of the magnetic material, wherein the diamagnetic or paramagnetic matrix material is selected from the group consisting of a glass, a glass ceramic, and a ceramic, wherein the glass and the glass ceramic are based on at least one of SiO2, A12O3, Na2O, K2O, MgO, CaO, B2O3, TiO2, PbO, and P2O5, and the ceramic comprises at least one of mineral silicate ceramics, non-oxide ceramics, and oxide ceramics based on aluminum oxide or beryllium oxide, and (e) magnetizing the magnetic material in an external magnetic field, wherein steps (c), (d) and (e) may be carried out in any desired sequential order or simultaneously in any desired combinations.