US 10,892,091 B2
Permanent magnet, motor, and generator
Naoyuki Sanada, Kanagawa (JP); Shinya Sakurada, Tokyo (JP); Yosuke Horiuchi, Tokyo (JP); Masaya Hagiwara, Kanagawa (JP); Masaki Endo, Tokyo (JP); Takahiro Terada, Kanagawa (JP); and Hideo Chikaoka, Kanagawa (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed on Jan. 24, 2017, as Appl. No. 15/413,598.
Application 15/413,598 is a continuation of application No. PCT/JP2015/001640, filed on Mar. 23, 2015.
Prior Publication US 2017/0148568 A1, May 25, 2017
Int. Cl. H01F 41/02 (2006.01); C21D 1/26 (2006.01); H01F 1/055 (2006.01); B22F 3/00 (2006.01); F27D 3/00 (2006.01); B22F 3/16 (2006.01); C22C 38/10 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); H02K 1/02 (2006.01); H02K 15/03 (2006.01); H02K 1/27 (2006.01); F27B 5/04 (2006.01); F27D 15/00 (2006.01); F27B 17/00 (2006.01); F27B 9/12 (2006.01); F27B 9/39 (2006.01); F27B 9/38 (2006.01); B22F 3/24 (2006.01); C22C 38/00 (2006.01); H01F 1/053 (2006.01); H02K 21/00 (2006.01); H01F 1/059 (2006.01); C21D 1/00 (2006.01); F27B 9/30 (2006.01)
CPC H01F 41/0266 (2013.01) [B22F 3/003 (2013.01); B22F 3/16 (2013.01); B22F 3/24 (2013.01); C21D 1/26 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/10 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); F27B 5/04 (2013.01); F27B 9/12 (2013.01); F27B 9/38 (2013.01); F27B 9/39 (2013.01); F27B 17/0016 (2013.01); F27D 3/0024 (2013.01); F27D 15/00 (2013.01); H01F 1/0536 (2013.01); H01F 1/0557 (2013.01); H02K 1/02 (2013.01); H02K 1/276 (2013.01); H02K 1/2766 (2013.01); H02K 15/03 (2013.01); H02K 21/00 (2013.01); B22F 2003/248 (2013.01); B22F 2301/355 (2013.01); B22F 2998/10 (2013.01); B22F 2999/00 (2013.01); C21D 1/00 (2013.01); F27B 2009/3066 (2013.01); H01F 1/0596 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method of manufacturing a permanent magnet, comprising:
press-forming alloy powder in a magnetic field to fabricate a compression molded body, wherein a total weight of the compression molded body is not less than 200 g nor more than 2000 g;
sintering the compression molded body to fabricate a sintered body;
performing a solution heat treatment on the sintered body; and
performing an aging heat treatment on sintered body after the solution heat treatment,
wherein the solution heat treatment includes:
performing a heat treatment on a treatment object having the sintered body at a temperature TST of 1100 to 1200° C. inside a heating chamber having a heater;
transferring a cooling member into the heating chamber after the heat treatment and placing the cooling member between the heater and the treatment object, the cooling member including a first layer and a second layer on the first layer, the first layer having a first thermal emissivity of 0.5 or more, the second layer having a second thermal emissivity lower of less than 0.5, the first layer containing carbon, a metal carbide, a metal oxide, or a refractory brick, the second layer containing copper, molybdenum, tungsten, titanium, or stainless steel, and the first layer being faced with the treatment object; and
transferring the treatment object together with the cooling member to the outside of the heating chamber, and cooling the treatment object until a temperature of the treatment object becomes a temperature lower than a temperature TST−200° C.,
wherein in cooling the treatment object, a cooling rate until the temperature of the treatment object becomes the temperature TST−200° C. is 5° C./s or more, wherein the cooling rate is achieved by a combination of absorbing, by the first layer, heat emitted by the treatment object and reflecting, by the second layer, heat emitted from the heater, and
wherein the permanent magnet is expressed by a composition formula:
RpFeqMrCutCo100-p-q-r-t,
where R represents at least one element selected from the group consisting of rare earth elements, M represents at least one element selected from the group consisting of Zr, Ti, and Hf, p is a number satisfying 10.5≤p≤12.5 atomic percent, q is a number satisfying 27≤q≤40 atomic percent, r is a number satisfying 0.88≤r≤4.5 atomic percent, and t is a number satisfying 4.5≤t≤10.7 atomic percent.