# US 2022/0044853 A1 · NdFeB alloy powder for forming high-coercivity sintered NdFeB magnets and use thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0044853 A1 - Document ID: US20220044853A1 - Status: Published application - Kind: A1 - Application number: 17/395,494 - Filed: 2021-08-06 - Published: 2022-02-10 - Earliest claimed: 2020-08-08 - Assignees: Yantai Shougang Magnetic Materials Inc. - Applicants: Yantai Shougang Magnetic Materials Inc - Inventors: Kunkun YANG; Zhongjie PENG; Kaihong DING - Web page: https://patentgrep.com/patent/US20220044853A1 ## CPC - H01F 1/0572: {with a protective layer} - B22F 1/17: Metallic particles coated with metal - C23C 14/35: by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} - H01F 1/0577: {sintered} - B22F 2304/10: Micron size particles, i.e. above 1 micrometer up to 500 micrometer - 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 - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) ## Abstract The disclosure provides a novel NdFeB alloy powder for forming high-coercivity sintered NdFeB magnets. The NdFeB alloy powder includes NdFeB alloy core particles with a mixed metal coating. The mixed metal coating is formed by simultaneously vapor deposition of a) at least one high-melting metal M selected from the group consisting of Mo, W, Zr, Ti, and Nb; and b) at least one metal R, where R is selected from the group consisting of Pr, Nd, La, and Ce; or a metal alloy RX, where X is one selected from the group consisting of Cu, Al, and Ga and R is at least one selected from the group consisting of Pr, Nd, La, and Ce. ## Claims ### Claim 1 A NdFeB alloy powder for forming high-coercivity sintered NdFeB magnets, the NdFeB alloy powder including NdFeB alloy core particles with a mixed metal coating, wherein the mixed metal coating is formed by simultaneously vapor deposition of a) at least one high-melting metal M selected from the group consisting of Mo, W, Zr, Ti, and Nb; and b) at least one metal R, where R is selected from the group consisting of Pr, Nd, La, and Ce; or a metal alloy RX, where X is one selected from the group consisting of Cu, Al, and Ga and R is at least one selected from the group consisting of Pr, Nd, La, and Ce. ### Claim 2 (depends on 1) The NdFeB alloy powder according to claim 1, wherein an average particle size D50 of the NdFeB alloy core particles is in the range of 2 to 6 μm. ### Claim 3 (depends on 1) The NdFeB alloy powder according to claim 1, wherein a thickness of the mixed metal coating is in the range of 3 to 100 nm. ### Claim 4 (depends on 2) The NdFeB alloy powder according to claim 2, wherein a thickness of the mixed metal coating is in the range of 3 to 100 nm. ### Claim 5 (depends on 1) The NdFeB alloy powder according to claim 1, wherein a weight ratio of the metal R or metal alloy RX to the high-melting metal M in the mixed metal coating is in the range of 5:1 to 50:1. ### Claim 6 (depends on 2) The NdFeB alloy powder according to claim 2, wherein a weight ratio of the metal R or metal alloy RX to the high-melting metal M in the mixed metal coating is in the range of 5:1 to 50:1. ### Claim 7 (depends on 3) The NdFeB alloy powder according to claim 3, wherein a weight ratio of the metal R or metal alloy RX to the high-melting metal M in the mixed metal coating is in the range of 5:1 to 50:1. ### Claim 8 (depends on 4) The NdFeB alloy powder according to claim 4, wherein a weight ratio of the metal R or metal alloy RX to the high-melting metal M in the mixed metal coating is in the range of 5:1 to 50:1. ### Claim 9 (depends on 1) The NdFeB alloy powder according to claim 1, wherein the mixed metal coating is formed by magnetron sputtering. ### Claim 10 (depends on 2) The NdFeB alloy powder according to claim 2, wherein the mixed metal coating is formed by magnetron sputtering. ### Claim 11 (depends on 3) The NdFeB alloy powder according to claim 3, wherein the mixed metal coating is formed by magnetron sputtering. ### Claim 12 (depends on 4) The NdFeB alloy powder according to claim 4, wherein the mixed metal coating is formed by magnetron sputtering. ### Claim 13 (depends on 5) The NdFeB alloy powder according to claim 5, wherein the mixed metal coating is formed by magnetron sputtering. ### Claim 14 (depends on 1) Use of the NdFeB alloy powder according to claim 1 for preparing a sintered NdFeB magnet. ### Claim 15 (depends on 1) A sintered NdFeB magnet produced from the NdFeB alloy powder according to claim 1. ### Claim 16 (depends on 15) A sintered NdFeB magnet according to claim 15, wherein an average particle size D50 of the NdFeB alloy core particles is in the range of 2 to 6 μm. ### Claim 17 (depends on 15) A sintered NdFeB magnet according to claim 15, wherein a thickness of the mixed metal coating is in the range of 3 to 100 nm. ### Claim 18 (depends on 15) A sintered NdFeB magnet according to claim 15, wherein a weight ratio of the metal R or metal alloy RX to the high-melting metal M in the mixed metal coating is in the range of 5:1 to 50:1. ### Claim 19 (depends on 15) A sintered NdFeB magnet according to claim 15, wherein the mixed metal coating is formed by magnetron sputtering.