US 11,854,725 B2
Soft magnetic metal powder, method for producing the same, and soft magnetic metal dust core
Tomofumi Kuroda, Tokyo (JP); Yu Sakurai, Tokyo (JP); and Tomohisa Mitose, Tokyo (JP)
Assigned to TDK CORPORATION, Tokyo (JP)
Filed by TDK CORPORATION, Tokyo (JP)
Filed on Nov. 13, 2018, as Appl. No. 16/189,725.
Claims priority of application No. 2017-220706 (JP), filed on Nov. 16, 2017; and application No. 2018-168892 (JP), filed on Sep. 10, 2018.
Prior Publication US 2019/0148044 A1, May 16, 2019
Int. Cl. H01F 1/147 (2006.01); C22C 38/02 (2006.01); H01F 41/02 (2006.01); H01F 3/08 (2006.01); H01F 1/24 (2006.01); C22C 38/00 (2006.01); C22C 38/34 (2006.01); C22C 33/02 (2006.01); B22F 1/16 (2022.01); B22F 1/065 (2022.01); B22F 1/142 (2022.01); B22F 1/148 (2022.01); H01F 1/153 (2006.01)
CPC H01F 1/14766 (2013.01) [B22F 1/065 (2022.01); B22F 1/142 (2022.01); B22F 1/148 (2022.01); B22F 1/16 (2022.01); C22C 33/02 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/34 (2013.01); H01F 1/24 (2013.01); H01F 3/08 (2013.01); H01F 41/0246 (2013.01); H01F 1/147 (2013.01); H01F 1/153 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A soft magnetic metal powder comprising metal particles including iron, silicon, boron, carbon, and oxygen,
wherein an amount of boron contained in 100 mass % of the soft magnetic metal powder is 0.010 mass % or more and 2.0 mass % or less,
an amount of carbon contained in 100 mass % of the soft magnetic metal powder is 0.120 mass % or more and 0.350 mass % or less,
an amount of oxygen contained in 100 mass % of the soft magnetic metal powder is 0.1000 mass % or less,
the amount of carbon is 3.125 times or higher than the amount of oxygen,
boron nitride is formed on a surface of the metal particles,
a roundness of 80% or more of the metal particles is 0.80 or higher, and
85% or more of the metal particles consist of one crystal grain.